If you’ve done much mobile development, you’ll know that what happens to your app when you switch away from it is very much at the mercy of the OS. While this is true on the desktop and the server as well, on mobile the OS is very focussed on maximising battery life, and so will be much more restrictive about background activity.
For the most part this is not such a big problem, once you’re aware of it. Pawel wrote an article awhile ago about responding to app lifecycle events, so that you can know when the OS is about to put your app to sleep, wake it back up again, etc. You can also create Services on Android to have longer running processes that survive separately to the app. And of course, this is why we have Push Notifications, so that the OS can start the correct application when it receives a notification, even if that application is not currently running.
Or at least that’s how it’s meant to work. (more…)