Yes. Just install that app. Ultracorder...
downloaded 1.0.5 as 1.0.6 says "not supported in your country" dunno why XD
I do see a huge difference in terms of light plus the stock camera is way farrrrr zoomed in compared to the ultracorder, light is way better on ultracorder, but it doesnt have no working functions, no stabilization nothing at all, could be useful at night times but i dunno needs more testing
Edit:
I did a little video testing (in 4k mode in both cameras)
1) In low light conditions, yes the ultracorder does perform better.
2) In terms of heavy light conditions (day light, under the sun), the stock does appear to have better handling, but in low light it sucks bad.
Conclusion:
would I use the Ultracorder as my default video taking app?
No. Why? simpley because in heavy light it doesnt perform better than stock, even a little worse plus it doesnt have any useable function like the stabilization, or slowmo etc...
BUT, I would definitely use it under low light conditions as it seems to out-perform the stock by so many levels, plus its not zoomed in like the stock, and it makes low light videos look a lot better in terms of everything except the stabilization, but i would definitely make it my default go to when in low light conditions!
but in daylight I would prefer the stock, but great job on the lowlight by Ultracorder, definitely will be so useful in night condtions.