Abstract-This paper presents a location-aware educational game for the iPhone/iPod Touch platform. The game, KnowledgeWar, is a quiz game where students can challenge each other in face-toface or remote knowledge battles. The game contains a game lobby where players can see all who are connected, and the physical distance to them. The paper describes our experiences from developing KnowledgeWar and results from a user test followed by a questionnaire. The user test focused on usability, and how well the game was suited for learning. The results showed among other things that the game had high usability, it is helpful for summarizing topics, it can stimulate involvement and social interaction, and that smartphones are well suited for such games. The results also revealed that our game did not to stimulate students to attend more lectures or pay more attention during lectures.