Halide is a fully featured iPhone ($1,000 at Amazon) camera app that gives you all kinds of control that you can't get with the stock iOS Camera app. For times when you aren't snapping a quick shot, Halide lets you manually set the focus, shutter speed, ISO and white balance. And you can shoot in the raw file format. The app's manual controls are easy to use and well worth Halide's $6/£6/AU$10 price. There are two portrait mode features, however, that make the app worth your while even if you have zero intentions of ever touching Halide's manual controls.
If you've got an iPhone with FaceID via the front-facing TrueDepth camera --, , or -- then Halide lets you up your selfie game with portrait-mode selfies. Because why shouldn't you be able to blur out the background when snapping a selfie with a camera that senses depth? Just tap the Depth button and Halide will find the edges of the foreground object (read: you). You will see white, lightning-like lines flash around your head -- that's the app separating you from the background. Halide calls this Depth Peaking.
There are two different options for previewing the depth effect:
Tap the portrait button and you'll get a live preview of you in front of the blurred background. Halide calls this Portrait Preview.
Tap the button to its left and you'll see a black-and-white depth map that can help you make sure the edges between the white foreground object and the black background are where you want them to be. Halide call this Depth View.
iPhone XR-only: Doggy portraits
I don't know about you, but I take many more photos of my dog than I do of my kids. One of the drawbacks of the iPhone XR is its lack of the second, telephoto lens that lets you snap portrait-mode photos. The iPhone XR uses machine learning for depth-effect photos with its single lens, but the object must be a human person. Halide lets XR owners take portrait mode shots of their dog (and other cute beasts) -- or any object at all. Just tap the Portrait button to line up an impossibly adorable and artistic photography of your dog, cat or chinchilla.