Android is an open source mobile operating system with massive user base and simplified mobile app development process. An Android app is a software application running on Android platform. Android platform is built for mobile devices. A typical Android app is designed for a tablet, a Smartphone or PC running on Android OS. Android apps are written in the Java programming language and use Java core libraries. This app can be made available by developers through their websites. Android apps are uploaded and published on the Android market. The Android market features both priced and free apps. Enterprises are leveraging Android and creating custom mobile apps that solves their customer problems and boost up the value for their business. The Android operating system is a multi-user Linux system in which each app is a different user.