GMB programs are well presented and cover an interesting range of movements and techniques for mobility and strength. Tutorials and videos are very clear and I've found their staff very responsive. However, although it is improving, their program organisation is not always logical or good for progression - two of their older programs, Vitamin and Mobius, now discontinued, were a bit of a grab bag of exercises, individually interesting, but wildly different in demands (so Vitamin would be a basic forward roll, followed by something like coffee grinder, a movement you cannot learn in 15 minutes unless you are way, way beyond the level of a forward roll). Their newer programs seem to be better, but be cautious about expecting to learn these moves unless you are already quite physically competent. The other big issue is their reliance on a web-based interface rather than an app - it's clunky and very vulnerable to service interruptions or poor reception. Still, I highly recommend Mobility and Elements for beginners.