As you may know, Yawls is an open-source software that automatically adjusts the screen brightness through the webcam, adapting the screen readability to the moment of the day and the weather condition.
The software is ideal when you use the laptop in either sunny or dark places. It is available as a command-line tool or via simple and intuitive GUI.
The latest version available is Yawls 1.2.1, which has been recently released, bringing the below changes and fixes.
Up to date packages are available via some third party PPA, so installing the software on Ubuntu should not cause too many headaches. Just add the PPA to your system, update the local repository index and install the yawls package:
$ sudo add-apt-repository ppa:thedsweb/yawls-daily
$ sudo apt-get update
$ sudo apt-get install yawls
Optional, to remove yawls, do:
$ sudo apt-get remove yawls
The installation instructions should work on Ubuntu 15.04 Vivid Vervet, Ubuntu 14.10 Utopic Unicorn, Ubuntu 14.04 Trusty Tahr, Ubuntu 12.04 Precise Pangolin, Linux Mint 17.2 Rafaela, Linux Mint 17.1 Rebecca, Linux Mint 17 Qiana, Linux Mint 13 Maya, Elementary OS 0.3 Freya, Elementary OS 0.2 Luna, Deepin 2014, Peppermint 6, Peppermint 5, LXLE 14.04 and Linux Lite 2.