Most trackers look like something issued by a dystopian correctional facility. The Pop ($150) comes across as, well, an analog watch.
The small dial displays progress toward your daily step goal, with the rest of your data sent via Bluetooth to your phone. The waterproof metallic body houses an accelerometer that provides sleep metrics and can differentiate between running, walking, and swimming, while the silicone strap fends off water and sweat. An intuitive app lets you analyze data and set goal reminders. And a watch battery powers the Pop for eight months. withings.com
Ease of Use: 4