I'm a self-diagnosed completionist and I hate the infinite scroll so much that I developed a mental habit that helps me work around it. When I visit a site with infinite scroll (e.g. YouTube or new Reddit) I immediately scroll down until the first loading spinner (e.g. by pressing the End key). At this point I stop and go back up processing the items in reverse order. This might sound silly, but it gives me a sense of completion and a natural exit point once I get back to the beginning.
I've been working on a Chrome extension called Hide Feed that automatically hides the feed. It's not quite yet ready for prime time, but it should help remove the need for that habit because you can just hide the feed whenever you don't want to look at it anymore.
I've been looking for something like this ! Definitely interested (will you open source it?)
I'm doing this manually using Stylus for facebook and twitter. It's unbelievable how healthier it made my consumption of these sites. I couldn't find stylus for mobile firefox though...
On Facebook, create a "list" of all of you're friends, bookmark the list, and use that bookmark as your portal.
The list will show you posts and shares from those people (in actual chronological order), and nothing else.
You're done scrolling when you see something you recognize from a previous visit. Congratulations! You've reached the end of Facebook. Visit again another day.