In our tests, the Rhythm+ did prove to be highly accurate, and was nearly comparable with top-of-the-line chest straps like PolarPro. And the accuracy of the Rhythm+ makes this device especially good at recording spikes in your heart rate from weight training or calisthenics, where most fitness monitors fall short because they take less heart rate measurements.
The Rhythm+ works with most popular fitness apps like MyFitnessPal and Nike Run, as well as ANT+ connected exercise equipment. Battery life is pretty superb at 8 hours, so you should be covered for your longest workout regimens such as day hikes and marathons. The Scosche Rhythm+ can be picked up for $79.