Android applications for electronic money website. -- 2

Need a developer for android apps.
The number of applications for development is 5 pieces.
Applications up to 700 pages.
Languages
Objective-C, Ruby, JavaScript, HTML, TypeScript, Java
• Frameworks
Flutter, React Native, Redux, GRPC, Electron.js
• Libraries
Node.js, React, Fabric, MagicalRecod, Slak API, Flurry, jQuery, Salesforce API
• Platforms
firebase, sales force
• Paradigms
Cross-platform, Model View Viewmodel (MVVM), Model View Controller (MVC), object-oriented design
(OOD), imperative programming, functional programming, agile software development
• Storage
Oracle
• Another
WebSockets, RESTful Web Services, Stripe Payments
Mobile Application Development Process:-
1. Application Programming - Programming application screens (front end) for Android.
2. Application / writing an application backend for the electronic money site API.
3. Application programming on the server side. Writing all the code on the server side to implement internal functions.
4. API development - writing all the APIs that connect the application screens with the server application.
and database.
5. Usability QA - Testing app screens for bugs and fixing any issues.
6. Multi-platform, multi-devices, OS versions, QA resolution - testing the application on all different
Android platforms and different OS versions;
Android OS has the following popular versions:
android 5.0 lollipop
android 5.1 lollipop
Android 6.0 Marshmallow
android 7.0 nougat
Android 7.1 Nougat
Android 8.0 Oreo
Android 8.1 Oreo
Android 9.0
Android 11.0

Payment under the contract for 5 applications 500 thousand Euros.
Form of payment - after the full development of all applications,
the developer will withdraw 10% of the site's profit up to the amount of 500 thousand Euros.
Application production time is 6 months. Write your suggestions in message