Octotree 7.12.1 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. This free software for Mac OS X is a product of Octotree. The program lies within Developer Tools, more precisely Webmaster Tools. We recommend checking the downloaded files with any free antivirus.
From the developer:
Octotree is a browser extension that enhances GitHub code review and exploration. The application provides you with IDE-like code tree, folder and file search, GitHub dark mode support, private repositories support, and repo/file/issue/pull request bookmarking. The tool allows you to work with repositories of any size.
You may want to check out more software for Mac, such as RAGE Domainer, ModelBaker or iGooMap, which might be similar to Octotree.