First look: Fitbit Ionic is packed with fitness, guidance & music storage

This isn't Fitbit's first smartwatch but it does lay claim to several firsts. For starters it has Fitbit OS based on Pebble's software (Fitbit acquired Pebble last year). This enables the Ionic to offer a variety of customisable watch-faces and support for third party apps. Plus, it can measure blood oxygen, something that most other fitness bands don't. It is also the company's first water resistant (up to 50m) smartwatch with a dedicated swim mode. Watch now.