The development of an Android app for the study of four-link mechanism with the same number of revolute joints is presented. The created app requires a complete study of planar kinematics: position, velocity and acceleration, setting one of the grounded joints as the input. Besides calculating the position, velocity and acceleration of the moving elements, the application also classifies the mechanism, according to the Grashof Law. The feedback received from the students that have already taken courses related to the application topic was used in order to quantify the app performance. The results of the app calculations were validated through comparison against results of widely known textbook problems, and with similar computer running tools as well.