This is the companion phone app for HR Monitor on the Samsung Gear S2 & S3.
You can use HR Monitor for free during one week. After that, you have to pay for this app once. The app will let you know how to pay. Purchasing is done in this way to give you the opportunity to test the app before purchasing.
When you uninstall the phone app, also uninstall the Gear app. Else the phone will notify you that the phone app is missing.
You can use HR Monitor stand alone, without Gear device, if you only want to synchronize heart rate and steps from S Health to Google Fit.