Compatible with iOS 11 and 12
This tweak will show an confirmation alert ("Keep Video?") whenever a video is about to be saved through the Camera app.
When the "Yes" option is selected, the video will be saved to Photos normally.
When the "No" option is selected, the video will be saved into the "Recently Deleted" album.
Developed thanks to a bounty from reddit user /u/jkister
Open source on Github
No options to configure.