In order to build a strong body, you need to work on strengthening your core. There are plenty of moves and tools that can help you develop more defined abs and strengthen upper body. These interactive core trainers make exercise more fun:
Stealth: an app smart core trainer that brings games to your workout sessions. It supports 360-degree motion for a complete workout, targeting 29 core muscles.
Nexersys Cross Body Trainer: an interactive trainer for MMA and boxing fans. It combines with an iOS/Android app to give you a full body workout. It has a wireless sensor to detect strikes, speed, power, and accuracy.
StaBallizer: it turns workout into games, so you can control games by squatting or planking. It serves as an ab roller, push-up handles, aerobic steps, and medicine ball.
Have you found better app smart core trainers? Please share them here.