Jupiter developed The World Ends With You, but didn’t work on the iPhone version, The World Ends With You: Solo Remix. H.a.n.d. (short for Hokkaido Artist Network and Development) reworked the combat system and redrew artwork to support Retina display devices.
H.a.n.d. and Square Enix have been working together for a long time. Final Fantasy Fables: Chocobo Tales, Kingdom Hearts 358/2 Days, and Kingdom Hearts Re:coded are all from H.a.n.d. They also developed some of Square Enix’s early iOS and social games such as Sliding Heroes and Chocobo’s Crystal Tower.
What’s Jupiter doing these days? They finished an educational game starring Doremon for Nintendo 3DS, made Tales of the World: Tactics Union, and an EKG training app for Android.