How do you get an emulator on the mobile phone gba or nintendo ds on android?

How do you get an emulator on the mobile phone gba or nintendo ds on android?

In the Google Play Store

You can download an emulator from the Playstore (Android).

You have to download the Roms or the Games from the Internet.

For the GBA you could get the "My Boy!" Download the emulator in the Play Store. For the Gameboys before that the "My OldBoy". Have used this myself for a long time!

However, you still have to see for yourself how you can get to the Roms, because Nintendo has put a stop to that.