For a long time I have been looking for an extension where I can "store" or "separate" my open tabs and send them to another place to read them later, and not something like wallabag and not necessarily offline, but simply for example leave saved the url of this post to see it later, without the need for it to be a news.
This is the extension and this is its Github page and its last update was just 3 weeks ago, so far in my opinion it works absolutely perfect.
Now, to tell the truth I can't say if it works because the developer was aware of the mobile users or it's because Mozilla is working on getting more desktop extensions to mobile, but either way, I want to make it clear that it works fine on desktop too.
For those who are interested, here are the steps to add extensions from desktop to mobile, it also works in Firefox Beta.
You could use something like Omnivore for this (it's what I use), is free and open-source and have apps for iOS and Android