If, after installing this, your system doesn't go to sleep immediately when you tell it to, but hangs on a black screen for a while, it is this application's fault. Console logs list the app along with a "PM notification timeout".
A big improvement. Celsius and SI units were sorely lacking and are finally there. Also, an option to display both SI and U.S. customary units would be good. Also, better satellite coverage maps of Mexico and other countries would help.