One of the most updated Gameboy emulators for Android has just been updated:

Nintendo GameBoy/GameBoy Color emulator for Android has been updated. Changes:
* Fixed DropBox crash when app folder has subfolders.
* Fixed gamepad on Nvidia ShieldTV and other AndroidTV devices.
* Any input devices named as "virtual-*" are now ignored.
* Any virtual (android-16) and disabled (android-27) devices are ignored.
* Switched to the latest android-27 SDK.
* Now using Android build tools version 27.0.2.