Can’t afford, make time for, or simply don’t want a personal trainer? But you still want to learn about improving your form while working out? We have just the thing for you: the Ollinfit wearable personal trainer. Basically it’s a set of three sensors that strap onto various parts of your body—for example, your wrist and bicep while you’re doing an arm routine. As you workout, audio feedback corrects any mistakes you make. When you’re done, you can check out a post-workout report on your smartphone or tablet. Look it up on Kickstarter soon.