Nope the default behaviour is to suspend the app from processing to save power.
Your app (as a developer) must register with Apple to be able to perform any background processing and Apple app reviewers take a dim view on apps that request this but don't really need to. Even then, the whole app isn't running, just very small portions. For example 'Runkeeper' would log your positions but it wouldn't do any graphical work.
Again, OzRunways hasn't registered for background processing so when you turn off the screen or quit to the home-screen the app is suspended (paused).
When the iPad detects the GPS is no longer required it will turn it off after a few seconds and the little arrow in the top right disappears indicating this.
Read this:
iOS App Programming Guide: App States and Multitasking
