I’ve just started to scratch the surface of all the cool things iOS 8 can do, so much to learn! One of my apps presents a modal view controller that asks the user to select a date from a custom calendar view I built. The app displays photos and this modal vc is presented over an image, so I wanted the modal vc to be (semi) transparent, so the image could be seen behind it. I scoured the web but there seemed to be a lot of conflicting ideas out there and none of them worked for me. I happened to stumble upon a/the solution on my own, while poking around Attributes Inspector.
Select the (modal’s – i.e. the one you want to be transparent) view controller from your storyboard and then click on the Attributes Inspector. As you can see in the screen shot below, there are Transition Style and Presentation options now available. The Transition Style is just what you expect it is and for Presentation, you want to select Over Current Context. Viola! Crazy simple.
I’d be interested to hear what has worked for you in iOS 7, although backward compatibility is quickly becoming less interesting to me.