Virtual GameBoy (VGB) is a program that emulates the Nintendo GameBoy handheld on your mobile device. It runs GameBoy, Super GameBoy, and GameBoy Color games on your mobile.
VGB was the first ever working GameBoy emulator
Virtual GameBoy Advance VGBA is an application that emulates Nintendo's GameBoy Advance on your mobile.
It is only legal to play games you actually own on VGBA. You will first need to read a game from its cartridge into a file. This can be done with an inexpensive gadget such as Flash Advance Linker
MasterGear (MG) is a program that emulates 8bit SEGA videogames on your mobile. It runs games made for SEGA MasterSystem (Mark3 in Japan) and GameGear, as well as their predecessors: SG1000, SC3000, SF7000, and Mark2. MasterGear will also help hobbyists who still write software for these systems to debug their works without using rare and costly development hardware