GameYob, Drenn's open source Gameboy/Gameboy Color emulator for the DS and DSi mode, has been updated to version 0.4.1. Check out the change log for what's new in this edition, and be sure to join the on-going discussion linked below for more details about this homebrew project.
Change Log (07/16/13) said:
v0.4.0 •New Icon by Corbin Davenport
•Implemented Super Gameboy support
•Implemented scaling (for those who don't like borders)
•Implemented custom borders (for those who don't like scaling)
•Implemented autosaving (causes lag in some games; off by default)
•Added "Detect GBA" option to access the advance shop in the Oracle games
•Added Fast Forward toggle button
•Added "Sound Fix" option for very accurate sound timing; it may use more power.
•Added Rumble Pak Support for Ez-3in1 and Warioware Twisted carts (thanks to windwakr)
•Added support for Gameshark and Game Genie codes (thanks to LemonBoy)
•Support for Rockman 8, HuC1/HuC3 mappers and Robopon games (thanks to LemonBoy)
•Second screen's backlight is disabled when not needed to save power
•(partial) Stereo sound emulation
•Many more...