Not everyone can afford a personal trainer, so we’ve been there: scanning the gym to see if someone’s watching us try—and probably fail—at a new exercise. Fabian Welke developed GYMWATCH GmbH to help beginners with such workout woes and professionals refine their training.

If you’ve ever fretted over having the perfect form, or whether you’re lifting at the precisely right speed, GYMWATCH uses an accelerometer to verify and correct more than 900 exercises. Watch us put it to the test in this video by our partner Portico.

Popular Science is covering the coolest, most futuristic, and strangest gadgets and technologies at the 2015 International Consumer Electronics Show in Las Vegas. Catch our complete CES 2015 coverage all week long.