Mini games using Meks. These use some art assets from megamek (http://megamek.info/) and therefore these games are also licensed under the GPL (http://www.gnu.org/licenses/licenses.html).
To play the games visit the game's page: http://minimek.sourceforge.net
The newest game is called "RogueMek". It is a Rogue-like adaptation of the Battletech board game. In it you choose your mech then battle it out against multiple enemy mechs.
...The desktop version is available on Windows and Linux - an Android port of has been made by David Lee Evans (https://github.com/DavidLeeEvans/FLAW)
The game and all of its assets are licensed under the GNU General Public License Version 3 and may be modified, copied and redistributed under the terms of this license.