Here is another smart exercise device that combines with your smartphone to help you maximize each session. The Edge-Board Extension Trainer comes with curved wheels for arcing turns. It lets you activate a wide range of muscles in your body. You will be able to sync to the M-Trac app to track your results and log the # of reps.
The device comes with ergonomic handles and removable tray for your phone. The Edge-Board Extension Trainer is ideal for core and stability training. Ships for under $70 at this time.[where to find it]