The idea of this work is to create mobile application that would help people in fitness world regardless of their level of experience to keep track of their healthy habbits or habbits of their clients in case of fitness coaches. In the world of Android development new technologies are rapidly hitting the market, so in order to be a good Android developer, a programmer must constantly learn new things and expand their knowledge. One of the goals of making this application is introduction to new technologies in Android development. Every good application is built using some kind of architectural pattern. This application will use MVVM pattern as a architecture of choice, wich will be explained more detailed furuther into this paper. No matter what thenology we use to build our program on, the one thing that all programs have in common is that they use some kind of data. Here we will be introduced to JavaRx library wich retrives and process data on background thread of the application. As this application allows user to see information tha the previously stored, that information needs to be stored in some kind of database. Data storage in this application is achived by using thrid party libraries. At the end of this paper we will look at fully built solution and compare it to some of the existing ones on the market.