Abstract—This diploma dissertation presents the research, design and development of an Android application for the game of quantum tic-tac-toe. Initially we examined the rules that govern the game of quantum tic-tac-toe, the relevant algorithms for its solution and the capabilities provided by the Android development platform. Subsequently we implemented a Java library for solving the game, which was later used, with minor modifications, for the development of the Android application. The said application allows the user to play quantum tic-tac-toe games against other users or against the computer, in varying levels of difficulty. In addition, the game’s capabilities include finding the optimal move in a matter of seconds in every case. This feature comes as a result of extensive optimizations in the game-solving algorithm, such as alpha-beta pruning and move ordering.