The Reaction SM Dual app allows the users motor functional asymmetry to be assessed. The performer should touch the corresponding blue circle as quickly as possible. To assess this ability, the program offers five visual models that differ in the complexity of the impact of visual stimuli on the performer. * Model №1. The task of the first model is that the performer has to react with both hands to the same visual signals (5 stages). * Model №2. In the second model, the performer must react with both hands under the influence of a greater number of confounding visual signals (5 stages). * Model №3. The task of the third model involves performing actions with one hand or both, both under the influence of disturbing signals and without them (6 stages). * Model №4. The fourth model involves a gradual increase in the effect of visual confounding signals during testing (5 stages). * Model №5. The fifth model is the alternate performance of actions without confounding visual signals and under the influence of a greater number of them (6 stages). At the end of the test, the program offers to fill in the information about the performer and save the result. The results of test execution can be presented graphically and as a table (CSV format). Also, in the settings, you can save a JSON backup of your measurements anywhere (Save backup), add measurements from another device (Add backup), replace already saved measurements with new ones (Replace backup), or delete all data (Delete all data). This app can be used by athletes and teachers of specialised training institutions for educational purposes.