Android Quiz App Development

I'm looking for an experienced Android developer to create a mobile application similar to Testbook. The app will include the following core functionalities:

- App must be similar to (Testbook : Play store)
- User Registration and Login
- Quiz Section
- Progress Tracking
- Mock Tests
- User-Uploaded Questions via JSON and Firebase

The app should be built using Android Studio, Java, and XML.

Ideal Skills and Experience:
- Proficiency in Android Development
- Experience with Firebase and JSON
- Strong knowledge of Java and XML
- Previous work on quiz or educational apps
- Good UI/UX design skills

Please provide examples of similar work done.