Running this script does not change your commit history in your existing repos. It only adds commits in the repo you create.
$ git clone https://github.com/vipyne/github-graffiti.git
Customize STRING
in green_squares.sh
(optional. look here for more string "picture" choices (and more to come in the future.))
$ ./green_squares.sh github_username new_repo_name
Please be patient (: The script is writing a year's worth of commits. It also takes github a little time to clear its cache. If your profile page doesn't look different at first, give it a minute, then refresh.
Now your contribution calendar could look something like this: or this: