The goal of this bachelor thesis is a broadening of teaching materials of the Hejny method, specifically the Biland environment, with a mobile application containing generated tasks, which offers the practice on selected types of tasks to primary schoolers. The application was developed in a multiplatform game engine Unity and is language neutral, because it does not contain any texts. It is based on the principles of a didactic software development as well as principles of the Hejny method. The thesis contains a design and an implementation of four gradually intensifying levels with an option to create an own task assignment. The end application may help children to understand the basis of the binary system and teach them addition and subtraction. Our application was tested on primary schoolers.