The introductory part describes the topic of user interface design in today’s context. Later, the roles of UI and UX designers in application development are discussed in detail, with special reference to their mutual differences. Next, the Figma tool is introduced with an overview and explanations of its main and advanced features. The main part of the work focuses on the development of the “Fido dogsitters” application, which manages the online market for buying and selling pet care services. In further chapters, the target groups of the application’s users are described, and the mascot and graphic characteristics of the application’s design and, in general, the visual identity of the imaginary brokerage house that owns the application are presented. In the practical part of the paper, the detailed process of creating the design of the user interface and the prototype of the application is presented. All the categories within the application are elaborated and their functionalities are described in the context of the user flow. Each category is analyzed from the design and functional side, with an emphasis on interactive components. The conclusion summarizes the contribution of UI and UX design in creating an intuitive and visually appealing application, and the importance of tools like Figma in that process. It also states the findings that are the product of the research process during the creation of the design and prototype of the application.