You should never pay for a SNES emulator for any computer or mobile device. One of the best SNES emulators for Android is ported from Snes9x and is called Snes9x EX.
Most android devices running android 2.3 or higher should render full framerate. We also recommend a wireless bluetooth controller to get the best experience from your android emulator. Check with the controller's manufacturer before you buy to make sure it is compatible with your android phone or tablet. We tested the Red Samurai, which is made specifically for GameStop, and it works great on my Motorola RAZR Maxx, Acer Iconia A110, A200, and A500; but does not work with my HTC One.
The latest version of Snes9x EX: . [ Download for Android ]
Emulators for the Nintendo DS:
Ever wanted to play SNES games on your nintendo DS? This is possible with a flash cart such as the Supercard DS Two!
In my opinion, the Supercard DS Two is currently the best (and most expensive) flash cart ever made for the Nintendo DS. You can purchase one for about $40 USD from one of their many distributors.
This emulator doesn't run at full framerate on the DS due to the DS's limited architcture but I'll take what I can get. CATSFC is written specifically for the Supercard DS Two. Do not try to use this emulator with any other flash cart.
The CATSFC Homepage is at http://forum.supercard.sc/thread-11194-1-1.html.