Yahoo Sports says "if you need some motivation to get you through a 30-second or even a three-minute plank, this might be your new favorite fitness gadget.
Doing variations of plank workouts can help activate more than 29 different muscles in your body. It’s one of the easiest and most beneficial bodyweight exercises you can do. And with the Stealth Fitness Core Trainer, you play smartphone games with your body movements."
Check out the full review here: https://sports.yahoo.com/full-body-workout-while-playing-203531763.html