In general, really good. Great videos and tips, good variety with the randomization. More flexible than most such programs.
Room for improvement: One thing that would be really good when starting doing new exercises is if it played the how-to-do-it video while you were doing the stretch. It’s inflexible and doesn’t allow spontaneity that you have to watch the videos before you being the program.
Jajina about Performance Stretching - Foam Roller, Static, and Dynamic Stretches