iOS 8: You normally take photos on your iPhone by tapping the screen to focus, checking the light in your preview and tapping the screen. MultiCam changes it up by letting you shoot first, and worry about focus and light later.
The effect is similar to Lytro cameras. In MultiCam, you can choose the number of focus points (up to 15) and exposure levels (up to four) in each photo. Set it, tap the shutter, and hold the device steady as it takes a series of shots with different exposures and focus. Then check the app's gallery to see your image, with slider bars to adjust the exposure and focus. It all happens in real-time and is dead simple to use. Once you tweak the picture to your liking, save it to your iPhone's gallery and delete it from MultiCam (it will take up a lot of memory otherwise).
There's also a setting called "9 Area Focuses" which divides your screen into a grid of nine and takes shots focusing on each. This only works with a single exposure though. In image editing, much like with the previously featured Tadaa SLR, tap any area on the screen to focus there.