I have had fun exposing this app to my students, and trying it for myself! I use it for private or group string lessons, and I have noticed that the students are really paying more attention to pitch as a result. The only thing that I would like to see is an option to replay the two tones. I would highly recommend to all music teachers who are trying to help their kids develop discriminating ears, and for all music students who are trying to improve on intonation!
Mr. InstruMENTAL about InTune – Tuning Practice