Love it or hate it, the plank is one of the best exercises for strengthening your core. But planking can be a little boring, which is where the Stealth Core Trainer comes in. While it may look like a fancy padded board, it's got a sphere on its under side that sits in a base module. The design allows the top piece, and you to swivel from side to side and up and down as you hold the plank position. With your body perfectly parallel to the ground. The other key element is this little compartment toward the top of the board. It has four circular pads that are a little sticky and are designed to keep your phone from moving around while you're using the stealth app to gamify your planking workout. The app includes a simple game that uses your phone's accelerometer to move a target site over dots that appear on the screen. You have to hold the sight on the dot for a few seconds to get the dot to explode. Later on in the workout you have to precisely follow a set of smaller dots to get to your main target to maximize the number of points you score. It is very fun, definitly takes my mind off the workout itself cuz I'm so focused on trying to get those dots. And typically I normally hold my plank for like a minute before I start losing focus. And you know I was able to get to two minutes even without thinking about it. The Stealth Trainer and the ab combo really do create a great core workout. But could you use the app on its own with something else and get the same workout? I feel like you can use this app and mimic the same experience on a bosu ball. A good BOSU ball costs around $75. This, on the other hand, costs $300, but there is a $200 version that holds less weight and should work for most people. It is a little expensive, but I do think the Stealth is more comfortable to plank on than a BOSU ball and offers wider range of motion. Right now there's only one game, but Stealth is planning on adding new games in the future. [MUSIC]