KORG iM1 for iPad - MOBILE MUSIC WORKSTATION | KORG (USA)
Korg microKEY Air 37 MIDI Keyboard with Bluetooth
Korg Plugkey Mobile MIDI / Audio Channel Audio Plug-In; Play iPhone/iPad Using Any Keyboard
USB MIDI Keyboard Controller 25-Key as Gift for Son,Donner N-25 Portable MIDI Keyboard with Velocity-Sensitive Keys & Light-up Rocker for iPhone, iPad, Mac and PC. - Walmart.com
Is this possible? Korg Gadget "TaiPei" midi in and midi out at the same time. : r/ipadmusic
Korg MicroKEY air 25/MicroKEY air 37 - Key Bluetooth and USB MIDI Controller Connect wirelessly to iPad, iPhone, Mac, or Windows - AliExpress
Korg PlugKey Mobile MIDI / Audio Interface for iOS | Sweetwater
How to Use Your iPad as a Wireless MIDI Controller