This study examines music apps as independent instruments in instrumental lessons. Many apps provide experimental sounds that can be incorporated into lessons. The thesis defines terms and descriptions of apps, describes the use of apps in instrumental lessons and evaluates the selected apps using a self-developed guideline. For this purpose, literature studies were conducted, theoretically developed lesson concepts with apps were tested and analyzed, and a guide for self-evaluation of apps was created. The results show that the piano students are encouraged to discover new things by interacting with the experimental sounds of the apps. In addition, the apps make it possible to make music together with people who do not play an instrument, which can create additional music-making moments.