Wasn't sure if I should start a new thread to post this but this thread is a gem and seems like the right place to post.
As well as slowing down iRb to "40 bpm" and playing piano along to the chords (Piano Grids),
i've found this free app a great help. Been playing guitar for over 45 years. Piano playing 6 months!

http://www.better-ears.com/en/better-ears-mac.html