Kazam
VoxelShop
Kazam is a simple screen recording program that will capture the content of your screen and record a video file that can be played by any video player that supports VP8/WebM video format. Optionally you can record sound from any sound input device that is supported and visible by PulseAudio.
After many years of testing for a screen recorder, Kazam is by far the easiest to use and the most functional. The recording is crystal clear and does not put a huge load on the cpu/gpu. It also provides an icon indicator (top bar) that allows for easy access to pause or start/stop a stream.