octotree is a Chrome plugin that displays Github project code in a tree format, and in the displayed list, we can download specific files without needing to download the entire project.

Move the mouse over the icon on the left side of a file, and a download button image will appear; click it to download a single file:

Source code address: https://github.com/buunguyen/octotree

Download address:

For more installation methods, you can check：https://github.com/ovity/octotree/blob/master/README.md