"Carbon Footprint for Google Maps" is a browser extension for Google Chrome that aims at raising awareness of users w.r.t. the problem of air pollution caused by cars. Whenever the user asks Google Maps for driving directions, this browser extension automatically estimates and shows to the user the total CO2 emission for driving on the route suggested by Google Maps. "Carbon Footprint for Google Maps" is currently used by 20000 users and is installed by 20 new users every day.
Carbon Footprint for Google Maps in the Chrome Web Store: https://chrome.google.com/webstore/detail/carbon-footprint-for-goog/ednfpjleaanokkjcgljbmamhlbkddcgh
Github repository: https://github.com/OiWorld/CarbonFootprintGoogleMaps
GSoC Instructions: https://github.com/OiWorld/MindTheWord/blob/master/GoogleSummerOfCode.md