Use APKPure App
Get Release-Keys and Test-Keys detection old version APK for Android
Sprawdź klucz podpisywania jądra podczas kompilacji
Release-Keys and Test-Keys have to do with how the kernel is signed when it is compiled.
Release-Keys means it was signed with an official Key from an official developer.
Test-Keys means it was signed with a custom key generated by a third-party developer. From a security standpoint, Release-Keys generally means the kernel is more secure, which is not always the case.