> "endless puzzle game from maker of Joinz." - Author's description
[https://play.google.com/store/apps/details?id=air.com.gamebrain.twelve]
Download on the App Store
[https://itunes.apple.com/us/app/twelve-hardest-puzzle/id931004233] (iOS)
Download on Google Play
[https://play.google.com/store/apps/details?id=air.com.