The application can’t be opened because it may be damaged or incomplete.

Sometimes downloads or updates over the internet can go wrong. A new download should fix this.

Delete the damaged application

1. Open Launchpad
2. Type “Letter Opener” into the search bar
3. Click and hold the application icon until it starts wiggling, then click the x to delete the app
4. When prompted press “Delete”

Download on the Mac App Store

Click here to open the Letter Opener page in Mac App Store. Click “Get” and then “Install” to download and install Letter Opener for macOS again.

Restore your purchases

To restore any in-app purchases you made before, first open Letter Opener for macOS then go to Help > Purchase Information and click “Restore Purchases” in the following window.