(pronounced "no cash GBA") is a free Nintendo DS and Game Boy Advance emulator for Microsoft Windows & DOS. It is capable of running commercial and homebrew Game Boy Advance and Nintendo DSROMs, many at full speed. It is the first Nintendo DS emulator running commercial ROMs. However, this claim has been disputed by many in the emulation community. NO$GBA was developed by Martin Korth.
Information provided by Wikipedia
• Redesigned for iOS 7
• iPad Support
• Game Boy Color Support
• iOS 7 Controller Support
• Event Distribution
• Dropbox Sync
• Custom Controller Skins
• Sustain Button
IMPORTANT: Start the download with today's date. Once the download has started, open Settings > General > Date & Time, and set the date back to February 18, 2014, or earlier (if you get an error message, just ignore it). Once the download has finished, open the app, and set the date back to normal.
Information and download from here.