There exist several possible approaches to the development of mobile applications. The paper treats the options of native applications for mobile devices. It analyzes economic aspects of two approaches - native applications development with the help of tools for individual platforms (Windows Phone, Android, iOS) and native applications developed by cross-platform tools represented by the tool Xamarin. In the paper basic variables and a formula for costs calculation are defined. The conclusions show that the utilization of the cross-platform tool Xamarin can lead to significant costs reduction. However, further research is needed mainly in the area of both the complexity development by cross-platform tools and meeting the requirements on UI and UX.