You've probably seen videos on instagram of riders on homemade "manual trainers." These hold your rear wheel while vertically and have a tether to prevent you from falling backwards, the aim being to help you find the balance point so you can ride your rear wheel back from your ride like a boss. Tilt Industries has begun mass producing a much more refined version of this device, with the added utility of an optional work stand and a wall mounted holder to store your bike. Tilt doesn't advertise this as a manual trainer however; the idea is that the skills required to hold your rear wheel in the air in the stand will transfer over to the trail and make you a better rider.