I always visit my friends codechef profile to see what problems they are solving, how many questions they have solved in long challenge. So to automate this process I built CodeStalk.
CodeStalk lets you track your friends on codechef and sends email updates when someone in your track list successfully solves a problem on codechef! I have made the code open source so that people can help improve and add more features. For more info and code check the about section on CodeStalk I would be glad if people can put suggestions, reviews, bugs here.