Ribn is described as 'MIDI controller with 8 assignable ribbons. What makes Ribn unique is its ability to record and loop your finger movement. This allows you to add organic repeating modulation to your synths and effects, kind of like complex LFOs' and is an app in the Audio & Music category. There are three alternatives to Ribn for iPad and iPhone. The best alternative is Midi Studio. It's not free, so if you're looking for a free alternative, you could try Knob Lab.