AseDS

AseDS is a free Nintendo DS emulator, allowing you to play Nintendo DS games without actually buying a Nintendo DS. This provides a low cost gaming option for those who cannot afford a real Nintendo DS, or who want the additional customization options that come along with a software-only solution. AseDS features a unique interface that has touchscreen built in, the ability to save and load any game at any time, access to GameShark, Actionreplay, and Codebreaker cheats, as well as supporting wireless controllers and device microphones. That's just a start, as AseDS also features adjustable button layout schemes, a feature to bind keys, landscape and portrait orientation including auto-rotate, stretch to fit screen layout, and automatic frame skipping and flicker reduction. You can transfer ROMs straight into your storage device, as long as the filenames end in either .zip, .ds, or .rom.

To get started using AseDS, you simply open AseDS on your device, then after pressing the menu button you simply select "File Browser" when it appears in the popup menu. From that point forward, it's a simple matter of selecting your ROM file using your file browser, and opening it.