forum.xda-developers.com/apps/google-camera-mods/gcam-google-pixel-1-2-3-t3875663

P3v11_GoogleCamera_6.2.024.apk
-Rebased on Google Camera 6.2.024 (Clearing App Data is recommended)

As tested on a Pixel 2, all Pixel 3 features are enabled except: Motion Metering and Tracking Focus.
Synthetic Fill Flash is working.
Launcher Shortcuts for Portrait Mode and Night Sight
Includes various fixes specifically for the Pixel 1, Pixel 2, and Pixel 3.

P3 Mod Settings
-General
--Portrait Zoom options
---Off / Pixel 2 & 3 Default (1.5x rear, 1.2x front) / Pixel 3a Default (2x rear, 1.2x front)

-Night Sight
--Permanent Night Sight Suggestion
--Increase Tripod Capture Time
---Increases the frame count and exposure time when the phone is steadily mounted, in Night Sight.

-Pixel 3 Features
--Toggle of AI AWB in HDR Enhanced
--Top Shot toggle (must use Google Photos DayDream to view them)
--Photobooth toggle
--Focus Tracking toggle
---Not recommended. Focus Tracking cannot be disabled for only Video at the moment, and if you enable it in Video it breaks EIS on the Pixel 2 and probably Pixel 1.

-Experiemental
--HDR+ Config options
---I don't really recommend anything other than the pre-selected option
--Pixel Visual Core HDR+ Config toggle
---I don't really recommend this
--Super Res Always On
---Attempt to use Super Res everywhere possible, no matter the zoom level

Oreo is not supported.

If you are rooted, install this optional Magisk module to set SELinux to Permissive to the modded app(s) can use the Hexagon DSP just like the stock app.
forum.xda-developers.com/showpost.php?p=78520564&postcount=243
This reduces the processing time a small amount and may be more battery efficient. The modded apps appear to be blocked from using the DSP/PVC for Processing, by default.