For Android Subscribers:
- Visit the Play Store on your device.
- In the Play Store, search for the app.
- At the top of the page, click the Cancel button to stop your Premium subscription.
For more information on Google Play subscriptions
For iOS Subscribers:
- Go to Settings > [your name] > iTunes & App Store.
- Tap your Apple ID at the top of the screen.
- Tap View Apple ID. You might need to sign in or use Touch ID.
- Tap Subscriptions.
- Tap the subscription that you want to manage.
- If you're being charged for a subscription, but you don't see it in your list of subscriptions, it might be billed through someone other than Apple.
You can choose a different subscription offering, or tap Cancel Subscription to cancel your subscription. If you cancel, your subscription will stop at the end of the current billing cycle.
For more information on App Store subscriptions: https://support.apple.com/en-us/HT202039