The best mobile emulator is for Gameboy-GBc/Gameboy Advance, "Pizza Boy" amazing, you should definitely check it out, the emulation itself is nearly perfect as well : r/emulation
UltraGBA ( GBA Emulator ) APK for Android Download
John GBA Lite - Apps on Google Play
10 Best GBA Emulators for Android [2019]
Best Game Boy & Game Boy Advance Emulators for Android 2022 | Android Central
GitHub - pedrovgs/AndroidGameBoyEmulator: Android Game Boy Emulator written in Java