LUT Camera support
The watermark is still there after I paid
Open the app, tap "Remove watermark", then "Restore Purchase". Photos and videos taken before the purchase keep their watermark; new ones won't have it.
The camera is black
Check that LUT Camera is allowed to use the camera in your phone's settings.
Where are my photos?
In your photo library. On Android they are in Pictures/LUT Camera and videos in Movies/LUT Camera.
Contact
Email hankimproduction@gmail.com and I'll get back to you.