How to maintain record of my App's previous launch time

I want to restrict my app's launch based on the numb开发者_开发知识库er of times the user has accessed my app in between a particular time interval. So I thought that if I know my app's previous launch, I could achieve it. If there is something else possible , plz someone out there help me..

On your app launch, increment and store a variable in Shared Preferences. Check this at each start.