Here is a smart wearable device designed specifically for CrossFit enthusiasts in mind. Nexus goes on your arm to monitor how you train. It serves as your coach and lets you analyze your performance on your smartphone. Nexus has an ergonomic design and lasts up to a week on battery. It tracks your workout automatically and lets you compare your results with others.
Nexus is compatible with HealthKit, Google Fit, and MyFitnessPal. It can track over 140 exercises with more added all the time. It takes into account power, cadence, work-to-rest ratio, and strain on your body to help train smarter. Expected to ship in September.