Is it possible to develop the back-end of a native mobile app using the python powered framework Django?
Sure. I've done this for my first app and others then. The backend technology is totally up to you, so feel free to take whatever you like.
The connection between backend and your apps should (but don't have to be) be something JSON-based. Standard REST works fine, Websockets also but have some issues on iOS.
I want to develop a online mobile app. I am thinking about using native languages to develop the front-ends, so Java for Android and Objective-C for iOS. However, for the back-end, can I use something like Django?
I have used django for a while, but the tutorials are really lacking, so can anyone point me to something that will help me understand how to show data handled by Django models on a front-end developed by Java for an android device (that is, by using XML I suppose).