BattleShips3DS is licensed under the GPLv3, a copy of which can be found in the file LICENSE.txt.
All the ctrulib, citro3d, and citro2d contributors for the amazing libraries.
icons8.com for some images in the gfx folder.
Hydraxis#7824 for the icon
The eSpeak application for the enemy_dead.mp3 and ship_dead.mp3 in sounds romfs/sfx
OpenGameArt.org for the water texture in the gfx folder, modified to be darker/more blue and have the grid on top of it, and for the hit sound effect, in romfs/sfx, modified to be in mp3 (both licensed under the CC0).
Freesound.org for the sonar, miss and shot sounds in the romfs/sfx folder (licensed under the CC0), which have been modified to fit the game better.