The AirTurn PED can be used with SongBook+.
But it cannot be used in the "PED-APP-Direct" mode. SongBook doesn't support this mode yet.
All other modes that simulate an extrenal bluetooth keyboard can be used.
Here you find the needed settings to use the AirTurn PED with SongBook+:
1) Follow the user manualk of AirTurn to couple the AirTurn PED by Bluetooth with the iPad
2) Open the settings in SongBook+ (button with a gear wheel)
3) Select "Foot pedal settings" on the upper right side
4) Select "Keyboard simulating foot pedal"
5) Switch "Use keyboard adapter" on
6) Select below which key should execute what action
When pressing a foot pedal, the AirTurn is sending different keys depending on the configured mode.
After following the steps 1) - 5) SongBook+ can display which keys the AirTurn is sending when you press a foot pedal.
To do that, press the button "..." in the toolbar of the main list and select the option "Open MIDI / Bluetooth monitor". Then press the foot pedals and see which keys SongBook+ is receiving from AirTurn. Use this keys to configure the desired actions in step 6).