Error: “Revu” can’t be opened because it was not downloaded from the Mac App Store

Depending on your OS X Security & Privacy settings, you may see the following error message on your first attempt to open Revu. Follow the steps below to edit the security settings on your device and open the application:

1. Click OK in the message dialog.
2. From the Menu Bar, click > System Preferences.
3. Click Security & Privacy to edit your General settings.
4. In the section that reads Allow apps downloaded from, select Mac App Store and identified developers. You may be prompted to enter the username and password for the Administrator account.
5. Close the Security & Privacy dialog.

You can now open and register Revu without seeing the message.