Back when Nokia was known for making Windows-powered Lumia phones, the camera was one of their most praised features, and part of their impressive performance stemmed from the Nokia Pro Camera software, which gave you a degree of manual control most phones wouldn't. This February at MWC, Nokia announced that the software would be coming back to its Zeiss-equipped Android phones, and now it is rolling out for the Nokia 8.
— Juho Sarvikas (@sarvikas) May 31, 2018
This Pro version of the camera enables additional manual controls (in the vein of Nokia's Lumia phones) including features like ISO, white balance, shutter speed, and exposure compensation. The UI also looks pretty snazzy. It can be hard to come up with an intuitive layout for all those various controls, and Nokia seems to have done it.
Pro Camera was initially only available for the Nokia 7, but it should be rolling out to the Nokia 8 as part of a ~600 MB OTA some people are already seeing. I'm not sure how Nokia's OTA rollouts are handled, if they're geographically restricted for test markets first or if they hit everyone all at once, but Nokia 8 owners should probably be getting it in the coming days.
APK download and a modified port for non-Nokia phones
If you've got a compatible Nokia phone like the Nokia 8 and you're tired of waiting for the OTA, it may be possible to get the new camera app by sideloading the app update, which is up on APK Mirror:
A fellow by the name of linuxct has also done a modified port of Nokia's new camera app to other phones, with support for devices that use the Level 3 Camera2 API. Note: OnePlus devices may have problems with it—Oxygen OS has had incomplete/broken support for recent APIs for a while. The app is also still in testing, so other compatibility issues or general wonk may also crop up. Be sure to report incompatible devices back to the developer.