While using nulled Android app source code may seem like an attractive option, especially for developers on a tight budget, it poses significant risks:

Are you looking to or develop a custom app from scratch? What is the main feature you are looking for in the app?

: Android will not install unsigned apps. Use uber-apk-signer to sign your new APK.

The modified application is distributed via third-party app stores, forums, and Telegram channels. The Dangers of Using Patched Android Apps