I have a Samsung Galaxy S8 Plus Exynos with android 9.0 Pie and OneUI 1.0, not rooted.
I have searched for a Gcam apk to work with my phone with night sight (night mode) and eventually all features working
The solution that I found is the following:
First, I have installed:
Arnova's Advanced 1.5: GCam_6.1.021_Advanced_V1.5.190418.1850.apk (Arnova8G2, 2019-04-18)