Music Terms is a music dictionary app for the iPhone and Apple Watch. It include over 1,100 entries. And it is quite easy to use and access.
Beside the glance view contain “A term at a time”, to refresh your term at random choice. To enable the glance you have to enable it at the watch app of the iPhone.
To use the Apple Watch app, you have to own an Apple Watch and connected to iPhone 5 or above.
Besides learning the music terms, there is also a quiz page to practice your memory, and the score will show you how many correct answers you have achieved.