Hey there,
I'd like to post a positive review for the free Spotify HR app with a Spotify Premium account.
First, let's start with what Spotify HR is not:
- not developed or supported by fitbit; as far as I call tell, it is developed and maintained by a volunteer independent developer
- not an audio player or streamer for the versa; it is a remote control for your Spotify account which must be playing on another device such as your computer, phone or tablet for Spotify HR to work.
I use it on an iPhone XR on a Versa special edition with a Spotify Premium account playing on the phone or my desktop computer.
- The remote works fine. One can pause or skip songs. One can also choose a playlist from one's library.
- It also shows the time and your hear rate. If you tap on the heart rate, a shuffle icon appears and the 'HR' feature is activated; that is a "heart rate shuffle"; a shuffle that chooses songs based on your heart rate and the songs tempo (in bpm). Based on what I read in another thread, a premium account is required for the HR feature to function.
- One thing I especially like about the HR feature is when I'm relaxing at home, it's choosing the slower songs from the 3 207 songs playlist I'm listening to and if I'm working out, it's choosing faster songs! I don't have to change playlists based on what I'm doing or skip a ballad while I'm on the treadmill... 
There's a bug right now, as of last release (2019-05-02) where the app closes (quits or crashes) if you don't look at your watch for a while. I've opened a ticket with the developer and pray/hope for a fix.
I hope you also have a positive experience with Spotify HR.
Cheers!
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