There is now an iOS & Mac app for Quiztones. Tons of new features including over 40 frequency trainers (EQ boost & cut) and choosing source audio from your own music library.
Quiztones sounds pretty cool Dan. Mr. Soundman seems fun too.
I'd still offer that the best bet is to start playing around with EQs on real music and real mixes. The most valuable thing is not identifying frequency ranges in isolation, but understanding how they interact with each other in real productions.