*With regards to Dr. Heinz Doofenshmirtz

This will allow you to select text in a Sublime Text file, and see the highlighted lines on GitHub's remote repo, if one exists.

If you use Package Control, just install it from there. If not:

Clone this repo to your Sublime Text Packages folder (ST3 example shown below):

cd ~/"Library/Application Support/Sublime Text 3/Packages/"
git clone https://github.com/ehamiter/GitHubinator.git

The plugin should be picked up automatically. If not, restart Sublime Text.

The defaults should work for most setups, but if you have a different remote name, use GitHub Enterprise or default branch, you can configure remote, host, and default branch in the Githubinator.sublime-settings file:

{
  "default_remote": "origin",
  "default_host": "github.com",
  "default_branch": "master"
}

Select some text. Activate the context menu and select "GitHubinator" or by keypress (⌘\ by default, configurable in .sublime-keymap file).