SnoozeTabs is an addon, which also got some media coverage (German site, 2) and which I personally really like.
However it was not updated since May and especially the required addon signing part may be block this experiment quite soon.
So is there any future for this addon?
Probably move this to the add-ons criteria if you feel it is better suited there.
The author is an active member. Paging @bwinton
Hopefully he’ll get that and pop up here. Messaged him on IRC just in case, he’s away right now. 
Yeah, we had an All Hands meeting last week, where I was hoping to get some stuff done on SnoozeTabs (and Whimsy), but just couldn’t find the time. It’s definitely still on my plate, and there’s a new automated signing API, which should make it easy to get signed. I was hoping to implement the new design first, but if that slips much more, I’ll just sign the current one.
In the meantime, if anyone is interested in pushing it forwards, I would happily accept pull requests! 
Thanks!
Any news? I’m still worried about the addon signing part as this addon is already blocked in Firefox 43 which is stable currently.