Square Enix has revealed two upcoming games: one for iOS, and one for browsers. Both games are due this year, at least in Japan, showing the short promotional ramp-up time for non-console releases. They're titled Guardian Cross, and Crystal Conquest, respectively.
Andriasang reports that Guardian Cross is a free-to-play iOS card battle game, pulling together some of Square's talent. The concept is from Hiroyuki Ito, Akira Oguro is handling character designs, and Naoshi Mizuta is on music. It's due this spring, and a small teaser site has been put up.
The second game, Crystal Conquest, was being teased recently by Square. While it lacks the Final Fantasy name, the logo artwork is a clear reference to its style. It's also free-to-play, and will come to the Yahoo! Games portal. Andriasang reports that Square calls it a "real time battle strategy game." In practice, this means a team-based action game; the strategy comes from equipping your warriors with skills from your deck. Once your load-outs are prepared, you take on 20 vs 20 battles, using skills and summons to take down enemies. It also has a teaser site.
Both of these releases are for Japan, and so far Square Enix hasn't mentioned releases for either of these games in the west.