Applies to Launchkey Mini Mk3
To use the Launchkey Mini MK3 with an iOS device you will need an Apple Lightning to USB 3 Camera Adapter, which is available here.
Crucially, this adapter features an additional lightning port for you to connect a charger to. This will also supply additional power to the USB port and this is required to use your Launchkey with the iOS device.
Using an Apple brand adapter is required, third party adapters are not supported and are widely reported to not work.
Once connected, your Launchkey will send MIDI to apps that support MIDI.