Nowadays everybody has their phone in their pocket so because of this is worth to develop mobile applications, because an average man can run application on their phone. I am going to develop a tracker application, which based on one of my ideas. My idea is about, if we getting trouble, notify our friends and inform them about my current position. Android supports two programing language which are Java and Kotlin. I am going to develop a pilot application in both programming language and compare them. The main point is about the differences between the two-programming language and point out what are the pros and cons. In this project, I am going to introduce what is Kotlin new features and how we can use these features in Android platform to be able to make a better application. The written application goal is to introduce the Android specific technology and make a conclusion what are the pros and cons for the languages during the application development. These technologies are for instances activities, services, communicating with external backend like firebase, push notifications, recycle view and view holder pattern, handling permission and location. Try to use the best practices, which require a lot of research. To end of this project I will have knowledge about Android platform, and I will also learn a new programing language, which is Kotlin.