Once you have purchased a sound pack or Pro Feature, you should always be able to access them within the app, as long as you are signed in to the same Apple ID you purchased them with.
In-app purchases cannot be transferred between Apple IDs. If you have lost access to a sound pack or feature within the app, please check that you are logged in with the same Apple ID that you used to purchase the sound pack or feature.
You can check you are signed in to the correct Apple ID by checking your purchase history. Please see this Apple support article on how to check your purchase history.
Alternatively, you can check you are signed in to the same Apple ID by checking your emails for the invoice you would have been sent from Apple for the purchase.
If you are signed in to the correct Apple ID; Launchpad, Blocs Wave and Groovebox all have a restore function. All sound packs associated with your Apple ID but not installed on your device will appear here.
In some cases, when you’ve switched Apple ID accounts on a device, purchased sound packs or Pro features may not appear in the restore list. To resolve this, make sure you are signed in to the correct Apple ID and re-purchase one of the sound packs or Pro features you’ve already bought. This will refresh your purchase receipt and all of your missing purchases will become available to you again. You will not be charged twice for this if you are signed in to the same Apple ID you originally used for the purchase.
If you are a Launchpad Premium user and have lost access to features or sound packs, this may be because your Launchpad Premium subscription has expired, or you are not signed in to the same Apple ID the subscription is associated with.
It is also worth noting that changing your App Store region may make purchased features unavailable.