The ultimate guide to building a mobile app
Got a great idea for an app? Need a new way to grow your business? We tell you everything you need to know about building a mobile app in 2020.
Kotlin is a popular and powerful open-source programming language. It is the official language of Android development, allowing developers to create sophisticated, innovative apps. Kotlin simplifies and speeds up development, allowing ambitious projects to be implemented faster, with fewer lines of code. This makes it an attractive option for clients looking to build a highly functional app or website quickly and efficiently.
Kotlin Developers bring valuable experience and expertise to any project they take on, allowing clients to get the most out of their investment. They are experienced in app architecture and development, making sure that client’s apps function exactly as desired. They also have excellent problem-solving skills, ensuring any issue is quickly resolved. In addition, their understanding of the Kotlin language makes working with this powerful tool more efficient and effective for clients.
Here's some projects that our expert Kotlin Developer made real:
At Freelancer.com we want our clients to know that their projects will be handled expertly by professionals with extensive experience in building with the Kotlin language. We can provide you with an experienced Kotlin Developer who can make your ambitious projects a reality in record time. Together you can bring your plans to life quickly and efficiently, allowing you to reap the rewards of our collaboration as soon as possible. If you're interested in taking advantage of our expertise in the field of Kotlin development then please do not hesitate to post your project today so that one of our professionals can help bring your plans to life!
From 55,224 reviews, clients rate our Kotlin Developers 4.9 out of 5 stars.Kotlin is a popular and powerful open-source programming language. It is the official language of Android development, allowing developers to create sophisticated, innovative apps. Kotlin simplifies and speeds up development, allowing ambitious projects to be implemented faster, with fewer lines of code. This makes it an attractive option for clients looking to build a highly functional app or website quickly and efficiently.
Kotlin Developers bring valuable experience and expertise to any project they take on, allowing clients to get the most out of their investment. They are experienced in app architecture and development, making sure that client’s apps function exactly as desired. They also have excellent problem-solving skills, ensuring any issue is quickly resolved. In addition, their understanding of the Kotlin language makes working with this powerful tool more efficient and effective for clients.
Here's some projects that our expert Kotlin Developer made real:
At Freelancer.com we want our clients to know that their projects will be handled expertly by professionals with extensive experience in building with the Kotlin language. We can provide you with an experienced Kotlin Developer who can make your ambitious projects a reality in record time. Together you can bring your plans to life quickly and efficiently, allowing you to reap the rewards of our collaboration as soon as possible. If you're interested in taking advantage of our expertise in the field of Kotlin development then please do not hesitate to post your project today so that one of our professionals can help bring your plans to life!
From 55,224 reviews, clients rate our Kotlin Developers 4.9 out of 5 stars.I need a single Android application that combines two core utilities: an efficient memory optimizer and an antivirus module. On the cleaning side, the app should intelligently free RAM, close unnecessary background processes, and provide clear before-and-after stats so users see how much memory was reclaimed. The process must be quick, unobtrusive, and light on battery. For safety, I want a built-in antivirus engine offering real-time scanning and automatic definition updates. As soon as a new file is downloaded, installed, or modified, it should be checked against the latest signatures and heuristics without noticeable lag. Updates to the virus database have to run silently in the background over Wi-Fi or mobile data, with fallback scheduling if the network is unavailable. I’d ...
Building an Fintech Mobile First App. We’re looking for a passionate Mobile App Developer Intern or fresher with strong coding, Data Structures, and Algorithms skills to join our team at Instient.ai. Location: Greater Noida, India Company: Skills: Kotlin Multiplatform / Flutter Internship Duration: 3 Months Work Mode: In-Person only (No remote work) If you’re interested, please apply using the form below:
I’m planning a mobile application that will pair job seekers with job offers on both Android and iOS. The core build must include robust user profiles, along with a fast, accurate job-search experience supported by filters such as location, role … In-app messaging is still open for discussion, so I’m interested in hearing how you would implement or improve that layer while keeping the platform secure and scalable. The app will run dual-sided: one workflow for seekers and another for offers, each with its own dashboard and feature set. I value clean UI/UX, solid documentation, and maintainable code (React Native, Flutter, or Swift/Kotlin native—whichever you feel best fits the brief). Please share at least one live link or store listing of a similar app you crea...
I have a RecyclerView driven by a LinearLayoutManager. Card taps are currently picked up through an OnPress handler, and I already keep the underlying data in a ViewModel. The problem is simple: when a user opens a detail screen from any card and then presses the back button, the list always jumps back to the very top instead of revealing the card they originally tapped. I need the list to remember its exact scroll position so that returning feels seamless. You’re free to solve it however you feel is cleanest—saving and restoring the layout manager state, using the Navigation component’s back-stack handling, or any other proven method—as long as: • the previous scroll position is restored every time, • orientation changes don’t break the fi...
I need a skilled Android developer to transform my concept into a fully functional, Play-Store-ready application. The project targets the latest Android releases, so solid knowledge of native Android (Kotlin or Java) is essential. I’m open to modern frameworks such as Flutter if you can guarantee a smooth Android-only build. Scope • Translate my wireframes and user-flow notes into an intuitive UI that runs smoothly across common screen sizes. • Build the complete feature set we finalise together; possibilities may include push notifications, secure user sign-in, or even in-app purchases, so prior experience with Firebase, Google Play Billing, or similar services is valuable. • Integrate any necessary back-end APIs, set up local data caching, and ensure the app remains...
I’m looking for a skilled software developer to create a mobile application for Android devices. The main goal is to turn my concept into a reliable, user-friendly app that meets current Google Play standards. Key objectives: • Translate my idea into clear technical requirements and a development roadmap. • Build the Android application, using Kotlin or Java—or another modern stack you recommend—to ensure smooth performance on recent Android versions. • Implement a clean, intuitive user interface that follows Material Design guidelines. • Connect any necessary APIs or back-end services and handle data storage securely. • Test across multiple screen sizes, fix bugs, and prepare the final APK/AAB for submission to Google Play. Deliverabl...
I’m ready to bring a new social networking experience to both iOS and Android and I need a seasoned mobile developer who can take the concept from blank screen to App Store and Google Play release. The core objective is to create a responsive, stable and scalable app that feels genuinely native on each platform while sharing a single codebase where sensible. Here’s what I’m looking for: • A developer who has already shipped social or community-driven apps and can point to live examples. • Proficiency with Swift or Objective-C on iOS, Kotlin or Java on Android, and a proven cross-platform framework if you prefer to accelerate the build (React Native, Flutter, or similar). • Solid back-end knowledge to stand up user authentication, data storage, push n...
I’m building a stripped-down social networking experience that centres entirely on text messaging. The goal is an Android-only app where users can exchange real-time text messages and spin up group chats without the heavier extras of photo sharing or profile feeds. Here’s what I need from you: • A clean Android Studio project (Java or Kotlin) that compiles out of the box. • Core screens for recent chats, one-to-one threads, and group conversations. • Real-time delivery of text messages, synced across devices even on spotty connections. • The ability for any user to create, name, and invite others to a group chat. • Push notifications for new messages. • Basic message history stored securely in the cloud (Firebase, Supabase, or a compara...
I have a RecyclerView driven by a LinearLayoutManager. Card taps are currently picked up through an OnPress handler, and I already keep the underlying data in a ViewModel. The problem is simple: when a user opens a detail screen from any card and then presses the back button, the list always jumps back to the very top instead of revealing the card they originally tapped. I need the list to remember its exact scroll position so that returning feels seamless. You’re free to solve it however you feel is cleanest—saving and restoring the layout manager state, using the Navigation component’s back-stack handling, or any other proven method—as long as: • the previous scroll position is restored every time, • orientation changes don’t break the fi...
I already have the core screens in place for an Android agri-tech application that will serve three field-side user roles plus one admin panel. What I need now is an experienced Android developer who can take the project from this UI prototype through to a production-ready release on Google Play. Scope of work • Wire the existing layouts to a robust back end so that every user can input data, monitor it in real time and receive analytic dashboards that make sense in the field. • Build an alert and notification flow (push & in-app) to keep farmers instantly informed of anything that demands attention. • Integrate a payment gateway so transactions inside the app run securely and are audit-ready. • Prepare all artefacts required for Google Play publication, gu...
I’m building a new social-networking experience focused on fast, reliable messaging for Android. The scope is a native Android app where users can register, find friends, and chat one-to-one or in groups with text, emojis, and read receipts. Core deliverables • An Android Studio project written in Kotlin (Java is acceptable if you strongly prefer) • Clean, modular architecture (MVVM or similar) with clear documentation • Firebase, Supabase, or another real-time backend wired up for authentication and message sync • Basic material-design UI: login/signup, contact list, chat screen, settings • APK and source code ready for submission to Google Play, plus a brief hand-over guide While the first milestone covers messaging only, I’d like the codeb...
I’m ready to turn my game concept into a polished Android application and need a developer who can take the project from first prototype to Google Play release. The core objective is simple: build a fun, stable, and performance-optimised gaming app exclusively for Android phones and tablets. You will handle the full development cycle—coding, asset integration, basic UI, local data storage, and Google Play Services (achievements, leaderboards, cloud saves). I already have draft gameplay mechanics and artwork; you’ll weave these together, advise on the best engine or native stack (Unity, Godot, Kotlin + OpenGL, etc.), and keep frame rates smooth across common mid-range devices. Deliverables • One signed, installable APK ready for internal testing • Clean, we...
I need a production-ready Android application that lets gamers enter Free Fire and BGMI single-elimination tournaments using a dual-currency system. Players will spend coins to register, earn diamonds for every kill and final position, then redeem those diamonds for Amazon, Flipkart, or Google Play gift cards inside the app. Core experience • Clean, modern UI with separate weekly and monthly leaderboards that reset automatically. • Email-and-password login only; no social or phone auth is required. • Coins and diamonds must be handled by a secure, server-side wallet so no values are stored locally. • Offerwalls (Timewall, CPAlead, Monlix) should credit coins instantly once their callbacks fire. • I will supply my unity account—ads keep the app comp...
I’m moving forward with a fresh Android-only mobile application centred on social networking. The core idea is to let users create profiles, connect with friends, post updates, and interact in real time, but I’m deliberately keeping the feature set flexible so we can iterate together as the concept evolves. Here’s what I need from you: • A solid Android build (Kotlin or Java) that runs smoothly on current OS versions. • Clean, well-documented code pushed regularly to a Git repository. • An early prototype (APK) we can test on physical devices, followed by improvements based on feedback. • Basic backend integration—Firebase, Supabase, or a stack you recommend—for authentication, data storage, and push notifications. I’ll provide wire...
I want to launch a word-puzzle game exclusively for Android that can turn a profit on Google Play. The gameplay revolves around players arranging or guessing words, with a clear difficulty curve spread across multiple, well-balanced levels—the only mandatory feature at this stage. Please build the game in an engine you are comfortable with (Unity, Android Studio with Kotlin/Java, or Flutter are all fine) and include lightweight AdMob integration so the title can start generating revenue from day one. If you see other monetisation tactics that suit a word game, feel free to propose them, but keep the first release lean and focused on rock-solid core mechanics. Deliverables • Release-ready APK • Full source code and project files • Documentation on how to add or ...
Dukandar – Smart Offline Retail Business & Sales Ledger Dukandar is a modern Android-based business management application designed for small retailers, kirana stores, shopkeepers, and MSME businesses to digitally manage their daily sales, cash collections, online/UPI payments, expenses, profits, transaction history, and financial analytics — without depending on an active internet connection. The application follows an offline-first architecture, allowing business data to be stored locally and accessed instantly. It replaces traditional paper-based management with a clean, intuitive and mobile-friendly digital ledger. The app provides a centralized dashboard for monitoring Cash Collection, Online UPI Collection, Total Sales, Expenses and Net Profit, while its analytics...
I want to bring a new social‐networking idea to life on Android. The project starts with a clean slate, so you will be responsible for transforming my concept into a fully functioning app—from setting up the project structure through to a polished release build ready for Google Play. Core expectations • Design and develop the entire Android application in Kotlin or Java, following modern Material 3 guidelines. • Implement the essential social features we will finalise together (user sign-up/login, profile pages, posting, commenting, liking, real-time updates, and push notifications). • Connect the app to a secure, scalable backend of your choice (Firebase, AWS Amplify, custom REST, etc.) and document the API endpoints clearly for future maintenance. • Ens...
I need an Android APK that focuses on one clear flow: letting new or existing customers complete a payday-loan application quickly and securely. Core flow • Users land on an OTP screen, enter their phone number, and receive a one-time code to unlock the app. • After successful verification, they reach a single multi-step form that gathers their personal information (name and address), employment details, and bank information. • When the final step is submitted, the data should be stored safely in a backend or Firebase collection I can later review. Interface & tech notes • A lightweight, modern UI in Kotlin or Flutter is fine—choose whichever you work fastest in. • Keep the code organised so I can hand it to another developer later for interes...
I’m looking for a developer who can turn my idea into a fully functioning Android e-commerce app. The goal is to let users browse products, add them to a cart, and complete checkout smoothly on their phones. Key objectives • Build a clean, intuitive Android interface that loads quickly on mid-range devices. • Implement core e-commerce features: product listing, search and filtering, cart management, secure checkout, and basic order tracking. • Connect the app to a simple, well-documented backend (Firebase, Supabase, or another lightweight stack you’re comfortable with). • Integrate at least one popular payment gateway suitable for my target market. • Provide authentication via email or social accounts and store user data securely. Deliverables...
I want to bring “Good to my life” to the stores as a health-and-fitness mobile app focused purely on workout plans. The goal is a clean, intuitive experience that helps users choose or build routines, schedule them, and track completion without extra distractions. Here’s what I need: • Workout plans – the heart of the app. Users must be able to browse preset routines and create, edit, or duplicate their own plans. A simple calendar view for scheduling sessions and a progress log that checks off completed workouts will cover the first release. Everything else—nutrition or broader activity tracking—can wait; I prefer to keep v1 lightweight, fast, and maintainable. Please target both iOS and Android; the framework is up to you, as long as the UI fee...
I want to launch an Android app that lets users search a full catalogue of mutual funds, narrow the list with flexible filters (by category, risk, expense ratio, etc.), and then view clean side-by-side comparison charts of any funds they pick. MPAndroidChart—or another modern library—can be used for the graphing. Access to the app should be protected only by social-media sign-in. Google and Facebook SDK integration will be enough; I don’t need any email/password flow. Please build natively in Kotlin, following a clean MVVM pattern in Android Studio. I’ll hook up the final data source later, so include a well-defined repository layer and dummy REST endpoints plus a Room cache for smooth offline behaviour. Deliverables • Complete Android Studio projec...
I need a skilled Android developer to build a dedicated e-commerce application from the ground up. The core goal is to give users a smooth shopping experience on Android phones and tablets, so performance and intuitive UI patterns matter as much as clean code. Here are the essentials I must see in the first release: • Product catalog that lets shoppers browse, filter, and view detailed item pages • Shopping cart that updates in real time and persists between sessions • Secure payment-gateway integration (I’m open to Stripe, PayPal, or any PCI-compliant option you recommend) Everything should be written natively for Android—Kotlin is my preferred language, though Java is acceptable if it speeds up delivery. I will provide branding assets and product data ...
I’m ready to turn my concept into a polished Android application and need a developer who can take the idea from the first mock-up all the way to the Play Store. The focus is 100 % Android—iOS isn’t in scope for this phase—so deep experience with Android Studio, Kotlin or Java, Material Design, and the common Google Play services is essential. I’ll supply the core feature list and wireframes; you’ll translate them into clean, maintainable code, craft an intuitive UI, and set up analytics, crash reporting, and simple CI/CD. Along the way, please advise on testing, versioning, and publishing so we end up with an AAB/APK that’s fully Play Console-ready. Deliverables • Source code in my Git repository • Release-ready AAB/APK plus signed...
I need a lightweight Android app that can take data about an approaching chicken—distance, speed, or any other sensor input we decide on—and instantly predict the safest time for it to cross a road. The prediction should be shown on-screen in simple, clear language so a farmer or handler can act without hesitation. Core requirement • Predict road-crossing times in real time for a single or multiple chickens. I do not need location tracking or intersection alerts in this phase; the entire focus is on accurate, fast predictions and an intuitive user interface. Preferred approach You are free to work with native Android (Java or Kotlin) or a well-supported cross-platform stack such as Flutter or React Native as long as the final build runs smoothly on current Android v...
I’m building an Android-only mobile app and I need a self-contained AI “command skill” that works purely through typed input. The goal is simple: when a user enters a natural-language request in a text field, the skill should recognise intent, extract any required parameters, and hand the result back to the main app so we can trigger the correct feature or workflow. Here’s what matters most to me: • Accurate intent recognition on common, short queries as well as longer, conversational text. • Fast response times; round-trip latency under a second when using a cloud NLP service, or comparable speed when running locally with a lightweight on-device model. • A clean Android interface (Java or Kotlin—your choice) that exposes one callable fun...
I need a sleek, fully-functioning Android application where people can browse, search, and view detailed profiles of “rental boyfriends.” The first release is focused only on creating, editing, and showcasing user profiles—photos, short bios, preferences, and basic availability tags. No chat or booking flow is required yet; I simply want the profile layer done right so we can test the concept and gather early feedback. Core expectations • Native Android build (Java or Kotlin) with modern UI components that feel familiar to regular Play Store users. • Secure email / social sign-up and login, plus a lightweight admin view so I can verify and approve new profile submissions. • Cloud back-end of your choice—Firebase, Supabase, or a small custom A...
I’m developing a mobile application that must launch on both Android and iOS from a single code-base. Core functionality includes: • Secure user login • Credit/Debit Card Payment integration (Stripe, Braintree, or a comparable PCI-compliant SDK) • Order tracking with: – Real-time location tracking – Order status updates The interface should remain clean and responsive, and the back-end endpoints for authentication, payments, and tracking will be provided (or you can quote for building them if that’s your preference). Please outline: 1. Your suggested tech stack (e.g., Flutter, React Native, Kotlin/Swift separately, etc.) and why it fits. 2. A high-level milestone plan with estimated timeline for each phase. 3. Total cost and anything ...
I’m ready to bring a new social-networking experience to Android and need a developer who can take the idea from concept to a polished APK on Google Play. The goal is a smooth, modern interface that lets users create profiles, connect in real time, and share content easily. You would handle the full Android development cycle—UI/UX, front-end screens, back-end integration, and deployment. If you’re comfortable working with Kotlin or Java, Firebase or a comparable cloud back end, real-time messaging, push notifications, and secure user authentication, we’ll be on the same wavelength. Deliverables I’ll review for acceptance: • Interactive Figma or XML mock-ups for sign-off • Functioning Android app (API 28+) with key social features live on a ...
I’m building a full-scale OTT service inspired by Zee5 and now need the companion Android and iOS apps engineered from the ground up. The heart of the product is seamless, high-quality video delivery, so the app must comfortably handle both on-demand titles and a lineup of live TV channels with adaptive bitrate streaming, DRM protection and offline download capability where licences allow. Every user will sign in (email, social, or phone) and create individual profiles under the same account, so the codebase has to manage profile switching, watch-history separation and personalised recommendations in the future. Subscriptions will be taken through standard credit/debit card checkout on our server as well as native in-app purchases on Google Play and the App Store; you’ll wire ...
I’m building a platform where users can watch sponsored videos and earn money in return. The project has two fronts: a responsive web portal and a dedicated Android app that work seamlessly with the same back-end. Core flow • New visitors create an account or log in. • Inside their dashboard they see a queue of ads, watch them, and once the required viewing time elapses the reward is credited. • Earnings accumulate in a user wallet; when the balance reaches a threshold the user can cash out via an integrated payment gateway (PayPal, Stripe, or another widely supported option—you can recommend the best fit). • An admin panel lets me upload/manage ad inventory, set payout rates, monitor user activity, and handle withdrawal requests. • Each user...
Saya ingin membuat sebuah aplikasi mobile khusus untuk platform Android. Fokus utama tahap awal ini adalah mendapatkan versi dasar yang sudah bisa dijalankan agar ide aplikasi dapat segera diuji. Lingkup kerja yang saya harapkan: • Menyusun arsitektur proyek di Android Studio (Java atau Kotlin). • Mendesain wireframe sederhana untuk alur layar utama. • Membangun prototipe fungsional dengan setidaknya dua layar yang saling terhubung. • Menyiapkan dokumentasi singkat tentang struktur kode dan langkah build + install ke perangkat. Harap lampirkan file source code lengkap, APK debug, dan panduan setup singkat saat pengiriman.
Saya membutuhkan seorang programmer mobile yang dapat membangun aplikasi Android dari awal. Fokus utama saya adalah: • Merancang antarmuka pengguna yang intuitif dan responsif sesuai panduan Material Design. • Membangun fungsi inti (login, database lokal / remote, dan notifikasi push). • Mengintegrasikan API eksternal yang akan saya sediakan. • Menyiapkan build release, file APK, dan dokumentasi ringkas agar mudah dipublikasikan ke Google Play. Kriteria keberhasilan: aplikasi berjalan lancar di perangkat Android versi terbaru, kode bersih dan terstruktur (Kotlin atau Java), serta disertai panduan pemasangan singkat. Bila Anda memiliki portofolio proyek Android serupa, sertakan tautannya agar saya dapat meninjau kualitas kerja Anda. Saya siap berdiskusi menge...
Saya ingin sebuah aplikasi pendidikan khusus untuk perangkat Android. Aplikasi ini harus menghadirkan materi belajar interaktif—misalnya video singkat, kuis pilihan ganda, dan ringkasan teks—agar pengguna dapat memahami topik-topik dasar secara mudah. Ruang lingkup pekerjaan: • Rancang antarmuka Material Design yang sederhana dan responsif. • Bangun fitur utama: daftar modul belajar, pemutar konten (teks + video), kuis dengan penilaian otomatis, serta halaman rekap kemajuan. • Pastikan aplikasi dapat berjalan mulus di Android versi terbaru dan tetap kompatibel hingga Android 8.0. • Sertakan kode sumber lengkap (Kotlin atau Java), panduan build, dan file APK siap rilis ke Google Play. Kriteria penerimaan: aplikasi stabil tanpa crash, navigasi in...
Got a great idea for an app? Need a new way to grow your business? We tell you everything you need to know about building a mobile app in 2020.
Learn how to find and successfully work with a freelance Mobile App Developer for your next project.
Learn how to effectively work with freelance App Usability Analysts and optimize your app's usability. Maximize user engagement and conversion rates.