Ubuntu 16.04 Screen addition:

Source: https://www.maartenbaert.be/simplescreenrecorder/

To add a screen recorder to Ubuntu 16.04 use the following commands:

sudo add-apt-repository ppa:maarten-baert/simplescreenrecorder
sudo apt-get update
sudo apt-get install simplescreenrecorder

To add a screen recorder to Ubuntu 18.04 or later use the command:

sudo apt-get install simplescreenrecorder