Usually, you want to turn off the phone to meditate, but HeartMath's Inner Balance ($100) turns it into a Zen machine. A sensor clips to your earlobe, detects a pulse, and sends this data to an app on your iPad or iPhone that calculates heart-rate variability – a telltale sign of calm – and guides your breathing to improve the rate. "Most of us think stressful emotions just happen to us," says HeartMath CEO Deborah Rozman, "but a few minutes of meditation a few times a day can help you take that back."