Several weeks after being implemented in Chicago, Flu Shots — which Kompare made freely available on the code sharing site GitHub — was “forked” and implemented in Boston. Then in Philadelphia. And now in San Francisco. In each successive instance where it was implemented, local developers used data obtained from the new host city’s public health agency. What started out as a notable civic app for its high profile use in Chicago went on to become a prime example of the potential impact of civic software development and how important it is for cities to open up their data.