In our study, a mobile application is developed which is able to capture the guitar sounds played in real time and detect notes using signal processing techniques. In this application, user's performance is evaluated by comparing the played and the expected notes for any chosen song. Additionally, songs can be prepared manually within the application or automatically by transforming guitar notes provided by Musical Intrument Digital Interface (MIDI) files into guitar tabs. Our application is tested with different users and difficulty levels, and effectiveness of the application is verified.