We mentioned Sonic's Jewels (SJ7) the other day as coming to Windows Phone. The SEGA Game Gear and Master System emulator has been submitted to the Windows Phone Marketplace and should be made available to all in the next few days. Coming with a free trial, the emulator will ultimately fetch for $1.29 which we find to a great price for this well designed app.
We've playing with it for a few days now and while there is currently no sound (the devs are hoping to get that working in the future) we found the emulation and presentation top notch. The app is fluid, intuitive to use and has built in Skydrive support for importation of your ROM collection. With the ability for three saved-states per game, pinnable Live Tiles for each game and the excellent progress indicators, we're very impressed with the effort here.
We'll keep you posted when Sonic's Jewels goes live in the Marketplace in the next few days. Until then, enjoy our video tour.
Update: This app is now known as Blue Tomato.