This is the best yoga app Ive tried. Its very easy to create routines, and to customize them down to every detail--music, length, vocal cues, background. It even allows you to build custom poses (rarely needed as their pose library is pretty extensive). My only request would be to share routines in the Pocket Yoga app, and more easily with friends who are also using these apps.
MigraineNewbie about Pocket Yoga Teacher