Do you know what your Android app is accessing on your device? Do you know what permission you have given the app after you install it? You will be surprised that some games are accessing your phone call.
This website, Mobile Security, is an initiative by Norton. On this website, there is a Compare Widgets where you can key in names of Android apps and it will help you to understand more about the Permission given to the particular app.
I use it to compare the popular game right now, Draw Something by OMGPOP and another app, Twitter, from Twitter Inc. You will be surprised that the game app is actually monitoring and recording your call (according to the results of this widget).
Hover the mouse cursor over to the highlighted cell and you will get more information about it.