Mobile Developers of this generation want their apps to be available on all the platforms. For example: - iOS, Android and Windows Phone etc. Since each platform works on a different environment and a completely different language it gets difficult for developers at times. Because of this we can see the beginning of many cross- platform technologies which can help to achieve different platforms. But in reality it is tougher to achieve all the platform-specific Native features and specially to get the performance similar to native applications. With crossplatform technology you can write the business logic once and shared among all the different platforms. Currently there are number of cross-platform frameworks which are available. In this paper we are focusing on Xamarin Framework. Xamarin is a cross-platform framework which promises many unbelievable features to build mobile applications. Xamarin claims whatever you used to do with Java, Objective-C or Swift, the same thing you can achieve with C#, a single language used by Xamarin. Accessing all the features of C#, and its .Net libraries you can build Android, iOS and Windows Native apps.