Great app for learning to differentiate between various pitches. The basic version is a good start, but most people would want the "pro" add-on for the extra $$. With that, I like that they give you an example track of a female vocalist, bass guitar, acoustic guitar, etc. and you are expected to tell what frequencies have been adjusted with those tracks. Its easy to get tired of hearing the same example track over and over, but I guess you could load some samples into itunes and use those for identifying various frequencies (instead of just using songs by your favorite artists). The grading system is very simple to understand and the layout looks great and is easy to use. Very happy customer here - Thanks (also, works great on iOs 8.3 - iPhone 6).
Musicinstructor about Quiztones: EQ Ear Training, v1.8.3