I wanna create a mobile apps using IBM MobileFirst Platform Foundation. The app should have a timer, and when I close the application, timer still running. So if the apps has not been used for long time, it will uninstall itself. I hope can get a draft idea how to make it, now I cannot find any material about it (API or others....). Thanks in advance.
It is not possible in MobileFirst Platform Foundation, and in general, to have an application uninstall itself. At the very least you could write a service in Android to do the timer, but not in iOS (maybe only in iOS 8 with app extensions), but still - your scenario is not valid. An application cannot uninstall itself.