forScore by forScore, LLC: A very full-featured music reading app that allows you to download or scan in music for use in rehearsal and performance. Features include a robust cutomizable annotation interface and seamless integration with bluteooth devices like page turners and styli.
Musician's Kit - Tuner, Metronome, and Sound Recorder by Kevin Murphy. This is the metronome connection. Impressed by taking it from the iPhone and iPad to an amplification system. Has everything you need to be successful. The recorder option is definitely not a solid choice for use. Better off with basic garage band.