Originally released for the Sega CD as Lunar: The Silver Star in 1992, the RPG later received an enhanced remake called Lunar Silver Star Story for the Sega Saturn in 1996, before eventually being ported to the PlayStation 1 in 1998. Since then, it has also received three further remakes/ports, including Lunar Legend for the Game Boy Advance, Lunar: Silver Star Harmony for the PSP, and the previously mentioned iOS port (which is pretty much an amalgam of the Sega Saturn, PlayStation, and PSP versions).
According to the game's publisher SoMoGa, Inc, the decision to bring Lunar: Silver Star Story Touch is part of a wider strategy that will see the company bring "titles both old and new beyond iOS". More information on this initiative will be available soon and the company is also teasing another separate announcement that will be unveiled sometime this Spring.
The Android port of Lunar: The Silver Star Story Touch is expected to be nearly identical to the iOS version and will include a bunch of quality-of-life updates You'll be able to pick it up from the Google Play Store on Android devices for $11.99.