After system dumps of the Pixel and Pixel XL devices were made available, developers have been busy porting apps to existing Nexus devices. We have already seen the Google Assistant being made to work on Nougat devices and the phone dialer too has been ported. But now its the new Camera app from Pixel phones which has made its way to Nexus 5X and Nexus 6P.
The Google Camera app v4.2 adds manual exposure control, long-press to lock exposure and focus alongwith faster speed. You can also set various grids on the view finder for framing your shot.
Now, this is a modified app which has been made to work with Nougat running smartphones. This won't install over your existing camera app. You can download the app from the link below, but it would only work on Nexus smartphones.