Multiple Choice Quiz Android App

I'm not a mobile apps expert, so I'll just write what's on my mind. Please give me your price based on the information below, then we can discuss other details. This app shall be in spanish and have the following: 1. Welcome screen with mode selection (beginner, advanced, full, etc). 2. Shall have 1000 or more questions in the app. 3. Basic 20 questions mode shall pick random questions within the selected difficulty (without repeating). 4. Upload to Android Store. Free version shall only support 20 question quizzes and include advertisement, paid version ($1.99 USD) shall unlock free and full modes and will be ad-free. Support payment through PayPal. 5. The quiz app shall count the user score and show the user the result after he/she finishes the quiz or when the user decides to finish the quiz even when he/she has not yet finished all questions (show total items, # of correct answers, etc). 75% correct answers is the minimum approval percentage. 6. This app is very basic and I am quite confident an experienced mobile app developer could develop this easily. Hence, the budget range is low. Expectations: I will own the full source code, app and all copyrights, etc. The source code will be well documented. Non disclosure agreement will be required. The architecture must allow for future addition of new APIs. Depending on your quality of work, I might contact you for further future development of this project. Developer must have a can do attitude and be willing to provide feedback and ideas. The app should work on all android versions and systems including tablets. The system design should be flexible for easy extension to other mobile OS such as BlackBerry, Symbiam, Apple iPhone/iPad, Windows mobile, and potential future web based product. Developer is an end-to-end solutions provider. Posting to the Android App store required. All testing will be 100% your responsibility. Bugs and other compatibility problems found after releasing will be your responsibility for up to 1 month after release. Payment Terms (Milestones): Beta Release: US$ 25%. Final Release: US$ 50%. Google Approval: US$ 75%. 1 month after launch bug and compatibility problem free: US$ 100%. Miscellaneous: This should be a very easy app to develop for someone with knowledge and experience in application development for mobile devices. If you think you are the Freelancer for the job, please bid and present the way you would handle this project. Describe the steps you would follow and what will be done in each step. Detail what you can offer and send examples of your previous Android/iPhone and other mobile OS work which are live. Note: must show previous Android work.