I've written a few iPhone and iPad apps over the years to help with my practicing. Two of them, DoubleTime Metronome and EarGuru, are available on the App Store.

DoubleTime Metronome   

DoubleTime is a metronome for working on your groove. With its state-of-the-art timing mechanism, it's as precise as it gets. But its killer feature is the DOUBLE button, allowing you to gradually extend the distance between metronome clicks as you dig deeper into your groove.


Only you can do the work of serious ear training. EarGuru helps you do it with three independent modes, each targeting a specific area: listening, playing, and singing.