If you're a music fan, chances are you believe that your hearing is finely tuned. Or is it? Here's a way to check it out.
AudioFile Engineering, a company based out of Minneapolis, has just released Quiztones 1.5. It's an "ear training application" designed for audio pros and musicians that can help you "instantly and intuitively recognize frequencies."
Why would this be important? Ask anyone who has ever done any audio mixing or EQing. Talk to a soundman who is trying to find the source of that feedback. Ask a guitarist who feels a particular tuning just isn't quite right.
Sounds like a right proper tool for some folks. It's $2.99 and is available for all iOS devices. Details here.