Tanglet - Tanglet is a single player word finding game based on Boggle.
Xmind - Xmind is a brainstorming and mind mapping application.
Crosswords Arena - Word game, multiplayer and computer players
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
Quackle - Open-source word game similar to Scrabble. Features a board editor, analysis tools, and artificial intelligence that rivals the best players in the world!
Coggle - Coggle is a simple, beautiful, powerful way of structuring information.