MTS Mobile is an Android app designed to aid in the study of the Method of Theory and Solfege (MTS) used by the Congregação Cristã no Brasil (CCB), especially in regards to Rhythmic Language. The app offers audio of the Rhythmic Language for all lessons from modules 1 to 11, as well as various hymns. It also includes a slower playback option for the more difficult lessons, an automatic update feature for hymns and solfeggios, and a calculator for time signature formulas with information on time unit, measure unit, motion figure, and more. In addition, there is a comparative table of figures and a metronome with speed markings for all hymns. It is worth noting that this app was developed independently and has no affiliation with the CCB. It is also a non-profit app, and any revenue from advertisements is used to cover maintenance expenses, keeping it free for users.