39 ritmos de violão - ritmando is an Android application developed by Mateus Polonini Cardoso, designed for people who already know the guitar notes and chords and wish to practice new rhythms to become a more complete guitar player. The app includes 39 different rhythms to practice, and it is aimed at those who love to play music on their guitar.

The developer has included audio samples in the app, which can be listened to and then played using your mouth before trying to play them on the guitar. This is a great feature for those who want to improve their rhythm and timing. The app also includes information on the major and minor harmonic fields, which can help guitar players to change the key of a song much more easily and quickly.

Overall, 39 ritmos de violão - ritmando is a great app for those who want to improve their guitar playing skills. It is clear that the developer has put a lot of thought and care into creating this app, and it shows in the quality of the content and the features provided. However, there is no way to contact the developer within the app, so any feedback or suggestions will have to be sent via email.