This master's thesis covers the fundamentals of React.JS sintax it's purpose as well as the needed tools and skills for mobile application development and building user interfaces. React.JS is JavaScript library used for building interactive user interfaces of web applications with reusable components. React.JS has many advantages, therefore today it is one of the most popular JavaScript libraries. Applications build with reusable components offer fast response to a user. React.JS automatically renders it's content on every change that user makes inside of the user interface. This way, the user has the insight of the application in a real time. Final product of this paper is building a functional mobile application using acquired knowledge and needed web technologies. The application has a role of Curriculum Vitae. It presents a candidate to employer, showing candidate's professional and social skills as well as the candidate's work in a portfolio. In such a way, candidate is being presented in a unique way, and also as the author of the application, candidate shows skills in application development. Except mentioned, the purpose of this thesis is seeing into new web technologies and their use in a multiplatform development.