So you have a listener who subscribed via in-app purchase to an ads-free version of your app, but now they want to cancel the subscription. Here's how:
They need to visit your station listing in the app store for their device and click to Cancel or Unsubscribe.
Google Play:
From the mobile device, they will see a link to "Manage Subscriptions" on the listing page and then can click to Cancel when they load that page.
AppStore/iOS:
How to cancel a subscription on your iPhone, iPad, or iPod touch
Open the Settings app.
Tap your name.
Tap Subscriptions.
Tap the subscription that you want to manage. Don't see the subscription that you're looking for?
Tap Cancel Subscription. If you don’t see Cancel, the subscription is already canceled and won't renew.
On the computer:
Open the App Store app.
Click the sign-in button
or your name at the bottom of the sidebar.
Click
View Information at the top of the window. You might be asked to sign in.
On the page that appears, scroll until you see Subscriptions, then click Manage.
Click Edit next to the subscription that you want. Don't see the subscription that you're looking for?
Click Cancel Subscription. If you don’t see Cancel Subscription, then the subscription is already canceled and won't renew.