GBC.emu cydia tweak is a full-featured Gameboy Color emulator.
Transfer games to your device using SSH or other file transfer method (The recommended location is any directory under /var/mobile/Documents or /var/mobile/Media). Make sure the “mobile” user has write access to the directory for save functionality. If possible use a program that mounts your device over USB like iExplorer (Windows & OSX), or ifuse (Linux) to speed up transfers.
This package comes with no games included. Do not contact the author for ROM images. This is an emulator, and requires ROM images. No ROMs are included.