Java App Bug Fixes

I have a Java app that crashes due to bugs. The app fetches data from a third-party website and delivers it via Firebase Realtime Database. I'm in need of a proficient developer who can utilize Firebase Crashlytics documentation to fix these bugs. This project will also involve future updates.

Key requirements:
- Proficient in Java app development
- Experience with Firebase Realtime Database integration
- Ability to fix bugs using Firebase Crashlytics
- Familiarity with Google Play documentation
- Java documentation and language grip as the errors in Java code mainly

The version of the app currently facing these issues is 80+.