Today, most people use mobile devices for various reasons. We can do many things such as calling, messaging, photographing and gaming through mobile applications. Even now, many people feel frustrated to the fastly decreased battery lifetime by using lots of mobile applications. How can we solve this problem? We find that context-aware application scheduling can be the solution. If we know the next application what we will use by several contexts, we will can preload that application or unload other applications to extend the battery lifetime with the minimal launch delay. We will consider about how to use contexts of users to find the best probability of guessing next application which will be used correctly.