Jarv Bluetooth HRM Chest Strap

Does anyone have one of these that syncs to an app on your phone? I was contemplating purchasing a HRM watch for non-running cardio activity (I have a Garmin GPS watch/HRM but it's really bulky to wear for other activities) but I came across this Jarv HRM strap that supposedly works with 3rd party apps.

I'd love to hear what apps folks use, android vs. iOS, experiences, etc.

Thanks!