I seem to change camera apps on my iPhone with the same frequency as my socks but I’m really digging Mattebox by Ben Syverson. It has some real nice controls and feels like a traditional camera when you use it. One of my favoribe bits is the virtual shutter slider. When you touch it, Mattebox locks the focus and exposure. You can then compose your shot with focus and exposure locked It acts just like a half-press on a dedicated camera. You then pull down the virtual lever to fire off a shot. Ben did a video explaining the app.