The steps to cancel your HeartBeat subscription depend on where you originally purchased it.
☝️ Deleting or uninstalling the HeartBeat app does not cancel your subscription.
If you subscribed through Google Play
To cancel your subscription on Android:
Open the Google Play Store.
Tap your profile icon in the top-right corner.
Select Payments & subscriptions.
Tap Subscriptions.
Select HeartBeat.
Tap Cancel subscription and follow the instructions.
You can also manage your Google Play subscriptions here:
If you subscribed through the Apple App Store
To cancel your subscription on an Apple device:
Open the Settings app.
Tap your Apple Account name at the top.
Tap Subscriptions.
Select HeartBeat.
Tap Cancel Subscription and follow the instructions.
You can also review Apple's official subscription management guide here:
Important
Make sure you are signed in to the Apple Account or Google account used to purchase the subscription.