I know how to implement the back button. My question is about the desired behaviour (as I experienced there is a hype around it that the good implementation of back button is required to sell the app in the store).
There is the official source: http://msdn.microsoft.com/en-us/library/windowsphone/develop/ff402536(v=vs.105).aspx#BKMK_BackButton
But I have never used a WP8 for more than 5 minutes. I understood that the "Windows" button/key is the same as android home and ios home buttons. Is it true, that the WP8 back should be the same as the android back? (Briefly navigate back through pages (screens/activities), dismiss alerts or cancel confirm popups, or if it is the first/only/final page/activity, the app should exit.)
As I experienced, there is a long-press on the back button, which brings up the app switcher (~ios double home). Is it true that I should not take care about of this button? Is the default behavoiur the same for the remaining buttons (windows, power off, camera (half and full), search)? Should I override them? Can I override them (I think I can use camera, but can I use volume controls for other purposes)?