Very tiny addon for fun and eyes relaxing Noté 5 sur 5 étoiles
It does what is promised and does nice.
As I understood, this addon is mostly for fun and relaxing.
If I understood properly, I have few proposals.
1. To vary the opacity via addon manager is a little bit boring. It is better to have an icon that can be placed by user on any toolbar that will allow to switch on/off the opacity by left click and choose the opacity level by top-down meny with right click.
2. If this addon is for fun, it is worth to give the user ability to "play" with color overlay or even to choose a wallpaper that also can be used (with very low opacity) as overlay