WHO, WHAT, WEARABLE Ear-O-Smart The first wave of activity trackers has largely been focused on the wrist. But Ear-O-Smart, a new device from tech start-up BioSensive Technologies, monitors the heart rate in a more accurate spot on the body—the earlobe. The smart earrings were designed to snap into jazzy, bejeweled interchangeable covers. What we liked: They don’t buzz, vibrate, or otherwise intrude on our physicality. They track health info using photoplethysmography (PPG) optical technology, which is Bluetooth-ed to any fitness app that allows you to link up a heart rate monitor. What we didn’t like: Statement earrings are back in a big way, but the ’80s-esque button-style design may not resonate with some fashion-forward consumers. Best features: This is low-fuss fitness tracking; simply put on the earrings and track your vitals from wakeup to bedtime. And the c