a GitHub App built with probot that checks before and after components between two Figma files and posts before after images.
This probot is customized to work with Octicons to look for changes in the figma import url found in the octicons package.json.
When there is a change in the url, this bot will pull down images for the before and after files and generate a before and after image for any changed components.
The documentation for writing your own Probot can be found on the probot website.