It is a sublime plugin to minify .js and .css file when you save them.
To work, you need to have the Minifier plugin already installed on your sublime.
a) Install Minify on Save via Package Control (RECOMMENDED):
First install Package Control - see installation instructions
Then, inside Sublime Text press ctrl + shift + p (super + shift + p on Mac OS X) and find Package Control: Install Package then press Enter.
You just need to search for the Minify on Save package and install-it (pressing Enter).
b) Alternatively, you can install Minify on Save from GitHub directly (NOT RECOMMENDED):
on Mac OS X:
git clone git://github.com/eltonvs/sublime-minify-on-save.git ~/Library/Application\ Support/Sublime\ Text\ 3/Packages/Minify
Note: Replace "Sublime\ Text\ 3" with "Sublime\ Text\ 2" in the above command if you are using Sublime Text 2.
on Windows:
git clone git://github.com/eltonvs/sublime-minify-on-save.git %APPDATA%\Sublime Text 3\Packages\Minify
Note: Replace "Sublime Text 3" with "Sublime Text 2" in the above command if you are using Sublime Text 2.
A lot of things can be improved on this plugin, make it better, feel free to contribute!
That's all, Folks!