I submitted a new game, Brain Battle 2, to the market last week. There is a free version and a paid version. The game lets you and a friend share a phone and try to answer questions over four different rounds (Math, trivia, objects, and combo rounds). Brain Battle 2 Free for Android There is a free version and a paid version. The paid version adds a single player feature, many many more trivia questions and high score lists. Please try out the game, and let me know what you think.