Nick Babich wrote a nice article about different ways of teaching gestures to the users of your Apps. Communicating non-obvious usage of an application is always difficult and many times results in long, tutorial-style launchscreens in apps. Nick makes a good case for ditching these kinds of methods and instead educating your users on-the-fly with inline hints.
If you have to give your app an instruction manual, then you’re not doing a good job of communicating with your users because users cannot be expected to read a manual before using your app.
Read the full article here: http://babich.biz/how-to-communicate-hidden-gestures-in-mobile-app/