App Store: https://itunes.apple.com/app/id411897373?mt=8&at=11l4FN&ct=nicovideo-video1Google Play: https://play.google.com/store/apps/details?id=app.letteropenerMac App Store: https://itunes.apple.com/app/id411897373?mt=12&at=11l4FN&ct=nicovideo-video1
http://www.nicovideo.jp/watch/sm39901970
