To prepare for the official release of the LEGO Hidden Side sets here in the US tomorrow, LEGO has also launched the LEGO Hidden Side app. You can now download it for Android and for iOS for free. The app is augmented reality based and you can use it alongside the sets to make them come alive on screen. There are a number of ghosts that you can fight and collect within the app. I’m sure many will not bother with it as the sets will be popular since it’s horror themed but it’s additional features that kids can enjoy.