Subscribed to a Newsstand magazine, streaming music service, or any other type of iTunes content and then later wanted to change or cancel your subscription? Well, there's no need to go running to iTunes on the your desktop. You can manage all your subscriptions right from your iPhone or iPad!
How to cancel or edit an iTunes subscription with iOS
Launch the Settings app on your iPhone or iPad.
tap on iTunes & App Store.
Tap on your Apple ID at the top.
Choose View Apple ID from the popup menu.
Enter your password when prompted and tap on OK.
Tap on Manage under Subscriptions .
Tap on the name of the subscription you'd like to cancel or modify.
Turn the Auto-Renewal option to Off.
After your current paid period ends iTunes will no longer bill you for that particular subscription. If you ever decide you want to re-subscribe you can do so either through the app or through hopping in the Settings app again like you just did.