The main reason I created this extension is the fact that it didn't make much sense to me the way the Twitter flow if you don't want to miss any tweet, I was always scrolling until I found my the last tweet I had read and reading things in inverse chronological order.
That said a new feature I will soon add to the extension is an option to mark the last tweet but go back to the top and start reading from there if you prefer that flow.
This is the github page: http://trufa.github.com/Remember-Last-Read-Tweet/ And this is here is the source: https://github.com/trufa/Remember-Last-Read-Tweet
The main reason I created this extension is the fact that it didn't make much sense to me the way the Twitter flow if you don't want to miss any tweet, I was always scrolling until I found my the last tweet I had read and reading things in inverse chronological order.
That said a new feature I will soon add to the extension is an option to mark the last tweet but go back to the top and start reading from there if you prefer that flow.