I know that pre-ios7 one could only get few things from outside of the sandbox, however... one thing that seems more common when using Apple's apps (!) is that they use a background which is the same as the springboard background.
One example is the "Reminders" app, which uses a translucent background of the springboards background.
I have search here and on Google, but can't find an answer to my question.
Is there anyway I can do this as well in my own app?
With default iOS background:
Onces the springboard background is changed:
Related post: Use user's Background Image as "theme"
I'm pretty sure Apple uses a private API to do this. I don't think they provide a way for developers to get to it - which is unfortunate, because it's a nice effect.