The theoretical part of the paper analyzes icons in detail, and today's standards of their design and usability testing, as well as the principles and methodology of user experience design. In the experimental part of the paper, the described principles and methodology of user experience design are applied through the design of a mobile application for the Android operating system. Special attention is paid to the design of icons for the needs of the application. The icons are designed in accordance with today's design standards and tested for usability according to four criteria: recognizability, intelligibility, findability and attractiveness. The criteria of recognizability is satisfied by the creation of icons whose symbolism corresponds to the mental models of the target audience. Then, the intelligibility of the icons was tested, which focused on a clear presentation of the meaning of the icons functions. Also, an examination of the icons findability within the mobile application interface and an examination of their attractiveness was performed. Since two sets of icons were designed - filled and outlined, the latter tests examined the impact of icon fillings on their visibility. It was found that filled icons are generally easier to recognize than outlined. Examining the attractiveness of icons, it was determined that outlined icons were more attractive than filled ones. Given the negligible difference in the time to find the icons of both sets, it was concluded that using outlined icons within the mobile application interface would achieve a better user experience.