TypeCatcher is a font manager with which you can search, browse, and download Google webfonts to use offline on your Linux workstation. It is created by Andrew and licensed under the GPL 3.0 and runs natively on any Debian-based distributions.
To install TypeCatcher and add it to your repository type these three commands into a terminal, one at a time :
sudo add-apt-repository ppa:andrewsomething/typecatcher
sudo apt-get update
sudo apt-get install typecatcher