Too bad there seems to be no further development.
I finally bought the paid version of the app after years of using it. It's the best you can get for unsuspecting filming.
I am also wondering if it's going to work with dual cams. I will probably order an LG G6 and try it.
It does, however, not record in 4K on a Galaxy S7 as soon as you're not on stock ROM but on LineageOS or the likes, which is certainly not SCOS' fault but a feature lacking in the custom ROM.
I also ordered a HTC U11 and will try to see if it does record in 4K when not on stock ROM.
In general, I actually didn't really see any improvements in 4K video quality compared to my Nexus 5X when trying it on a Pixel 2 and Galaxy S7, which is probably because SCOS is directly using the camera hardware without the manufacturers' software improvements (which are only integrated in their own camera apps), and camera hardware itself is not that much of a difference among different devices, with less aperture being compensated by bigger sensor pixels and vice versa.