A useful lens for Android users is the new Google Play Lens. Google Play Lens allows you to search Google Play for Android apps through Unity's dash. Once you click on one of the results the application's page will load on your default browser. To install Google Play Lens open a terminal and type:
sudo apt-add-repository ppa:abhshk-btra/rotatingcanvassudo apt-get updatesudo apt-get install googleplaylens
Once you have installed it log out and back in. For the time being this lens is available only for Ubuntu 12.04 Precise Pangolin.