In response to questions about the original post I've re-considered the scope and requirements of the project. Hopefully the updated document attached provides more clarity.
I've divided the overall app design into three stages, and the current project is only concerned with stage 1. This creates the basic app structure on which other features can be added later. I will provide all database content.
If this stage goes well then I hope to continue an association with the programmer to expand the app over the next few months.
The proposed app will help tourists visiting a geological site learn more about its history and importance. The app will be re-usable for other sites, and for various languages. I will own the completed app, provide the content (perhaps via Firebase) and arrange distribution. I need help with programming.
The attached doc outlines the basic structure I have in mind. Most of the content is master lists and detail text/image pages which I'm thinking would be best held in a Firebase database in order to facilitate updates and various app editions for multiple languages and sites. I'm open to other solutions. Interactive maps with vector polygon overlays are involved, as well as GPS tracking and PDF creation. I will supply text, images and kml map overlays.
The first geological site is in Italy and payment will be made from my Italian srl company so an Italian partner is preferred, but not compulsory.
Budget beyond that shown is possible, if justifiable, and not the only factor in finding a tech partneapp