Subscriptions renew automatically unless you unsubscribe. This applies both in Apple and Google. Find out how can you let your readers know how can they cancel their subscription to your app.
iTunes
Requirement: You will need to log in with the same Apple ID that you use with the subscription that you want to manage.
On your iPhone, iPad, or iPod touch
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 authenticate your Apple 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.
Use the options to manage your subscription. 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.
Google Play
On your Android phone or tablet, open the Google Play Store
Tap Menu Menu and then Subscriptions.
Tap the subscription you want to cancel.
Tap Cancel subscription.
Follow the onscreen instructions.
Important: Uninstalling an app will not automatically stop your subscription. You must cancel your subscription to end your subscription. If you uninstall the app without canceling your subscription, you will still be charged. If an app you've purchased a subscription for is removed from Google Play, your future subscription will be automatically canceled but past subscriptions will not be refunded.
Access after you cancel
When you cancel a subscription you will still have access to your subscription for the remainder of time you have already paid for. For example, if you purchased a one-year subscription on Jan. 1 for $10 and decide to cancel your subscription on July 1, you will have access to the subscription until Dec. 31. But you will not be charged another yearly subscription of $10 the following Jan. 1.