There are loads of great MIDI controllers on the App Store, from simple fixed-CC generators to elaborate construction systems for designing your own perfect touchscreen control surfaces.
Here are six of - in our opinion - the best, kicking off with Hexler’s touchOSC.
Using an application on a desktop computer, touchOSC lets you create your own Open Sound Control-based control surfaces, sequencers, DAW controllers and more, before loading them into your iOS device. It’s surprisingly easy!
One More Muse Control
Similar to TouchOSC, Control is a free app that gives you the power to create custom control surfaces that can be linked to target hardware and software through OSC or Wireless MIDI.
This one is open-source and available for both iOS and Android devices.
Justus Kandzi Trigger Box
This is a neat idea. Trigger Box generates semi-random gate and trigger signals through the audio output of your iPhone or iPad, which can be used to trigger analogue synthesisers and modules – though you might need to amplify the signal on the way to its target.
A step sequencer can be added for a buck.
Coffeeshopped Patch Base
Recalling the glory days of the universal patch editor/librarian, Patch Base is a free iOS app offering in-app purchase of individual instrument editors. At this time there are 30 profiles of popular synthesizers from Korg, Roland, Yamaha, Oberheim, Clavia, DSI, Casio, and Ensoniq, with more being added all the time.
Sonic Logic Knob Lab
Perfect for when you just want a few controls at your fingertips, Knob Lab is the handy little sibling to the powerful payware Sonic Lab, also from developer Uri Nachmias.
You get wireless control over MIDI hardware or even other MIDI apps. Well worth the download!
Crudebyte MIDI Wrench
The purely utilitarian MIDI Wrench is a visualisation tool for MIDI data. Plug any MIDI device into your iPhone or iPad and you can see - at a glance - exactly what MIDI data is online, and view messages as they’re sent.
Freely assignable virtual MIDI controllers and a keyboard are also in play. An essential tool for MIDI users.