"Futulele is simply the best-sounding Uke synthesizer in the world. The CrystalClear 4.0 sound engine works with 72 highest-quality Ukulele string samples, combining and tweaking them on the fly to deliver fantastic Ukulele experience. Futulele detects your strumming speed and alters the sound accordignly." See the support YouTube channel http://www.youtube.com/user/AmidioInc for the app in action.