The latest instalment in the Kingdom Hearts series will be on smart phone systems later this year. Kingdom Hearts Unchained Key will be available on iOS and Android systems.
Tetsuya Nomura first stated that a smart phone game for Kingdom Hearts would be announced soon. After a leak by Square Enix Germany, it was rumoured that the smart phone game might be a port of Kingdom Hearts x[Chi]. KHInsider started the hashtag "#ChitotheWest" to try and raise awareness for the game and in hopes that Square Enix would translate and open it up to a wider audience.
Today, Esuteru and Gamestalk announced that the game will be coming to Japan. The game is described as "Your player's avatar goes along gathering Lux (light) as a Keyblade Wielder.", which follows the basic plot of PC Browser game Kingdom Hearts x [Chi].
'Kingdom Hearts Unchained Key' for iOS/Android, scheduled to release 2015, free to play (with in-app purchasable items), the gameplay of 'Kingdom Hearts Key' remade for smartphones, setup for the plot has also been prepared for this newest title in the series. (@htmk73)
It seems that Kingdom Hearts x[Chi] is being revamped for smart phones and will feature new plot elements! It is unknown yet if it will be coming to the rest of the world but after the success of Final Fantasy: Record Keeper and other Square Enix smart phone titles, it seems highly likely.