SongBook+
It allows you to manage your songs with lyrics and/or sheet music, backing tracks, MIDI files, videos.
SongBook+ can remote control other MIDI enabled equipment by sending configurable MIDI commands when you open a song. SongBook+ can also be remote controlled with MIDI commands to remote open and display a specific music sheet.
You can add annotations into your music sheets and even add buttons to send specific MIDI commands on request. For bands, each musician can use SongBook+ with his/her individual music sheets, but they can be synchronized to automatically open the same song on all iPads.
SongBook+ can also be used as a multi-track audio player with up to 5 simultaneously replayed audio files, with global and per-song equalizer and even a loop function for those audio files.
SongBook+ can use a foot pedal not only to turn pages, but you can configure the action that is triggered by foot pedal buttons.
Platform: iOS
Cost: Paid, Free
MIDI Capable: Yes