In Days Since, each in-app purchase you make is available across all of your devices.
If you’ve previously made an in-app purchase and it is not unlocked, you will need to restore it. This will happen when you install Days Since on a second device or reinstall the app.
To Restore an In-App Purchase
Open Days Since
Tap on the gear in the upper left corner
Scroll down down past the in-app purchases to Restore Purchases
Tap on Restore Purchases
If previous purchases are found, they will automatically be unlocked again.
If no previous purchases were found, verify that you’re logged into the same iCloud account that made the original purchase.
If previous purchases are found but they are still locked, you can tap on the purchase button, next to the item you own, to unlock it again. Apple will not charge the same iCloud account twice for the same purchase.