Matrix Software was one of the powerhouses behind the surge of RPGs for the DS. They developed Final Fantasy III, Final Fantasy IV, Avalon Code, and Final Fantasy: The 4 Heroes of Light. Later they developed PSP games like Tales of Vs. and White Knight Chronicles Origins.
These days Matrix Software has been focusing on smartphone development. They did the ports for Final Fantasy III and Final Fantasy IV plus Final Fantasy Dimension. Matrix Software also handled the Final Fantasy V port which was is based on the Game Boy Advance version.
Right now, Final Fantasy Dimensions is on sale half off its steep $19.99 price tag. You can get the retro RPG for $9.99 on iTunes.