If you delete an app from device, and then download it again, you will see all your in-app purchases are gone (e.g. removal of adverts).
You can restore the in-app upgrade for free by selecting “Restore Previous Purchases” from the app settings screen (not the iPhone Settings app). You will be asked to enter your App Store account credentials, and within a few seconds all of your previously purchased items are restored.
First select Settings:
Then select ‘Restore Previous Purchases’
After confirming your Apple credentials, previous purchases are restored.
Please note that: ‘Jelly SMS Free’ and ‘Jelly SMS’ are two completely seperate apps. If you downloaded Jelly SMS (full version) from the start, make sure that this is what you install second time around. See here for instructions on downloading previously purchased apps.
Apple will always let you do the same purchase many times, and you will see a message popup saying ‘You have already purchased this item, press ok to purchase again for free’.
Sometimes people buy the in app upgrade in the app ‘Jelly SMS Free’, and then months later buy ‘Jelly SMS’ (2 different apps!). In this case, Apple will charge you twice.
To get a refund for the second purchase, please contact Apple directly. I cannot issue refunds as Apple don’t allow developers to do this.
Restoring previous purchases