Today while listening on Adventures in Angular podcast, I heard they mention this awesome and useful browser plugin called OctoTree created by Buu Nguyen. OctoTree is an extension / add-on for Google Chrome, Firefox, and Opera for viewing code tree on GitHub and GitLab. Safari user can also install and use this extension but since it is not available in the Safari gallery, you can use the prebuilt packages and drag it on to Safari to install it.
After installing this extension, you can navigate inside folders and view source codes easily in GitHub and GitLab. This extension also enable us to download the source code files directly with just a click. If you are someone who frequently browse GitHub or GitLab, this extension is a must have.