Here’s a cheaper (if you already own an iPhone) alternative to something like this…
This is a super fun way to perform / control different parameters in Ableton/whatever DAW you use. It’d be cool to take this live, however the latency (caused by WiFi, not the app) concerns me. Wifi is generally a bad medium for MIDI as there are so many other things that could be go through your network to slow it down. However the thing about Wifi is that a LOT of the latency has to do with the extra hop to the router. If you do an ad-hoc network, it’s mostly awesome. Latency is possible, but it’s almost never noticeable unless you have a large amount of interference. Hopefully we’ll see full Bluetooth MIDI arrive on iOS soon, in the meantime, this is still a pretty neat way to jam with your iPhone.
To set it up, add a control in MIDI Designer and double tap it to open its settings, go to Advanced tab > Accelerometer:
Assign a parameter in the synth you’re controlling to X and Y. You can also pick upside up or upside down to control up to 4 parameters – flip your iPhone upside down and you’ve got the other 2 controls. The accelerometer in the iPhone has pretty darn impressive precision, I’ve gotten some good results.