Why would someone use a transparent window background? Are people really reading the window behind it at the same time as the foreground window?

Example: If a build is going on in the background, I can see when it stops.

You can use `build-tool; tput bel` to hear the bell when it ends. Some terminal allows to set the urgent flag on the windows when the bell rings.

Yeah I have used desktop notifications for such things (via notify-send etc), but I'm going to accept this explanation for transparent background as it makes some sense to me.

pretty fun right :)

no.... and your screen shot completely fails to show off your tool

There is a pull request option - feel free to use it