In WoFF, you play as "Jiants", Lann and Reynn, who have the ability to summon mirages and "imprism" them. Although I think the prisms are actually called "Garden Gems" in japanese.
All the other NPCs and FF cameo "champions" are "Lilikins".

In the Meli-Melo mobile games, player play as their own Lilikin, but they also have the ability to summon mirages as "Garden users". However, unlike Balamb Garden in WoFF, Meli-Melo garden seems to be more of a literal farm-ville type "social" game app.

The mobile app was only available in Japan for a year before it ended it's service. So I can't dig up much on unique story content.

In WoFF, Squall talks about his dream to "fill the world with flowers". Like an actual flower garden.