The Fitbit One adds a number of welcome features to our favorite fitness tracker, including Bluetooth iPhone syncing, better water resistance, and a vibrating alarm that can wake you if you're using your Fitbit as a sleep monitor. The updates "enhance what was already a stellar product," according to PCMag, which calls the One a "super-smart pedometer" that "automates the hard work of keeping track of your overall fitness." Compared to the less-expensive Fitbit Zip, the One is "definitely worth the premium" according to TechCrunch, which calls the One "wonderful choice" if you want "a neat (and unabashedly geeky) way to keep tabs on how active you are."