Lemur does not produce any audio on its own. It is a controller app that sends and receives OSC and MIDI messages. Lemur is used to control music software, DJ software, video software, and more. Lemur is typically used to control software on a laptop, however using a MIDI interface you can use Lemur on your iPad to directly control outboard gear such as synthesizers. Lemur can also be used to control other apps running on the same device.