Android Ledger App Development

I'm looking for a simple ledger software that runs on Android. The app should only allow for credit and debit entries, making it straightforward and easy to use.

Key Requirements:
- Android platform support
- Simple interface for entering credit and debit entries
- User authentication via username and password

Ideal Skills and Experience:
- Experience in Android app development
- Familiarity with secure user authentication methods
- Ability to design user-friendly interfaces

Please provide examples of similar work done.