To change your subscription from monthly to yearly or vice versa, just follow these steps:
1. Launch the App Store app and navigate to the Featured tab.
2. Scroll down until you see your Apple ID. Make sure this is the same Apple ID you used to purchase the subscription.
If not, tap the button, select Sign Out and sign in with the Apple ID you used to purchase the subscription.
If you’re not already signed in, you will see a Sign In button. Tap the button, select Use Existing Apple ID and sign in with the Apple ID you used to purchase the subscription.
3. Tap on the button and select View Apple ID.
4. Under the Subscriptions section, select Manage.
If you have subscriptions other than DVO's, select Daily Devotions.
5. In the Daily Devotions screen, you will see the available subscription options under Renewal Options section.
If you are subscribed to the Monthly plan, the "1 month $0.99” option will be selected.
If you are subscribed to the Yearly plan, the "1 year $9.99” option will be selected.
6. Tap the subscription category for which you want to subscribe to.
7. You'll receive a confirmation message; tap OK to confirm your choice.