via http://www.aep-emu.de/

Marat Fayzullin has ported his (commercial) Game Boy / Game Boy Color and Super Game Boy emulator VGB to the Android platform: VGB for Android

Quote:
New in 3.5.10:
  • Made new portrait mode virtual joystick
  • Set default screen orientation setting to "auto".
  • Finally fixed the crashes on Samsung Galaxy S2.
  • Added optional haptic feedback, using vibration feature.
  • Added customizable button assignments.
  • Restored MENU button on Android Honeycomb.
  • Optimized joystick drawing routines.