Check out Arturia's take on this Oberheim classic dual-VCO synthesizer module with oscillator sync, pulse-width modulation and two-pole multi-mode filter.
Mira is the first incursion into the iPad app world from Cycling '74, makers of the popular Max graphical software toolkit for audio and media applications on Mac and PC. iTrigger is a grid-oriented MIDI controller app from POJ Studios.
Apple's iPad seems to have wormed its way into both live and recorded music in a big way, so having some way to hold the thing securely in the right position is a must...
Looking like a typical guitar effects pedal, iRig Stomp is actually a guitar interface that will work with iOS devices, and is compatible with most iOS signal-processing apps.