I first started this by modifying a Google Chrome plugin. Upon starting a new job in October 2018 I made a firefox version, unhappy with only having such functionality for Chrome. I keep mislaying my versions, so I have now put this into a Github
https://github.com/Lewiscowles1986/save-tabs-as-markdown-ff-chrome-poc and it's one plugin to handle Google Chrome as well as Firefox.
I never used the load functionality, and several browser options seemed needed to get it to work, so I lost it to make the plugin easier to understand. This uses no ads, analytics or telemetry, it's a thin wrapper on browser extension API's with a UI I find usable and intuitive.
