Citra is an emulator developed by EnergyCube. This emulator allows users to run Nintendo 3DS games on their Android device.
By installing Citra, players not only have access to games like The Legend of Zelda: Ocarina of Time 3D and Animal Crossing: Leaf but they also can play them better than if they were running off a 3DS. Improvements made by running games on Citra include resolution scaling so you can make the resolution of a game higher along with texture filtering to change out the textures of your game. Gamers who like to play with their friends will be happy to know that they can use Citra to play multiplayer games with anyone who's on their local network.
Overall, Citra is a fantastic emulator that can even be a better experience for those that love 3DS games. Some Android users should note though that Citra takes a pretty powerful phone if you're looking to run 3DS games well.