Scroll and Find by Haider Alwasiti

Don't worry about missing any social posts in your feed anymore! This extension returns you back to the last post you reached last time even after the feed was refreshed or you closed/reopened the tab.

Twitter backend server seems to refresh the feed every 10 hours or so and pushes the current position in my feed to the most recent. To catch up on my feed over the last few days and keep reading from the old posts to more recent ones, I will take a screenshot of what post and what date I reached last time so that the next day I will scroll back in time and search for that date and that post and continue from there.

This extension does that for you. Scrolls the chronological feed and searches for the phrase to catch that last post that you saw last time.

It is not specific to Twitter and can be used on any website (Facebook, Instagram, ...etc)

open source code:
https://github.com/hwasiti/Scroll-and-Find-Firefox-Extension