Wanna help move Apple to 50-billion app downloads? Well, you can keep downloading them one at a time or you can roll up your sleeves and build an app or two of your own.
No, it won’t teach you code. But the piece says it does walk interested parties through set-up, tutorials, fundamentals, and so on... it also provides “links to more extensive documents on each subject...”
Whether you're looking for a more general understanding, or want to build an application empire of your own, this may be a good jumping-off point.