Star6 [iTunes link], from Agile Partners, is a beat-mixing iPhone app with a lot of power behind its kitschy interface. While I see it being a fun toy for the casual user, there are some possibilities for great things, if you have the dedication to get good with it. I won't award it a heap of points for aesthetics, but the interface is highly usable and well thought-out.
You get six pads to which you can assign sounds, either from the array of included kits or from your own wav or aiff samples. Once you've got your kit loaded up, you can trigger the sounds in Grain mode, which makes it more of a sound effects machine, or in Sync mode, which will beat-match the samples to keep the rhythm flowing. While you're playing each sample, you can modify attributes like pitch, gate, speed, jitter and "size" by holding down each respective button and raising or lowering the iPhone. There were times in my trial of Star6 that I just wanted sliders, but the accelerometer-based manipulation has a definite right-brain appeal. Additionally, you can turn effects like delay, filter and distortion on and off whilst grooving away.
Star6 is running a contest right now, with two grand prizes of $500 each. You can see some of the entries by going to the YouTube Group, and join the group to submit your own. Details are available at the Agile Partners page for the contest. I'm a little late on the jump here, but the deadline has been extended to October 25th, 2009. It can't hurt to try, right?
Star6 is available in the App Store for $6.99US. Check out the gallery below for a few shots of the interface. If it looks interesting, though, definitely head over to the introductory video and samples (play before you buy) at the Star6 website.