Looks like Adventures of Mana (聖剣伝説 -ファイナルファンタジー外伝-) will be released on February 4, 2016 for iOS/Android. It's also coming out for Vita in Japan, and will cost 1,400yen.
English version trailer.
https://www.youtube.com/watch?v=_2Mu-lqV_BY
English version website.
http://www.jp.square-enix.com/seiken/en/
English version trailer.
https://www.youtube.com/watch?v=_2Mu-lqV_BY
English version website.
http://www.jp.square-enix.com/seiken/en/