I use this for almost as long as it's available on firefox, so I'm quite happy. The only thing I dislike it's that for some reason, when a segment is skipped, the youtube video do not always restart, loading in vain; if i manually move the playing time in the video, it plays normally without restarting the page. So I'm hoping this will be fixed because it didn't happen in the past (but since I do not often go on youtube, i'm not sure when it started to happen).

one of the best extensions on the internet. straight up just made an account to leave this review. a perfect 10/10 💖 you're the best Ajay, thank you so much for blessing us with this 🙏

Being able to consume media without the fluff of sponsors, being reminded to sub, intros and outros built into the video makes this a special extension, especially when you can do it on normal videos and music videos. Not only is this a crowdsourced extension that everyone contributes to, but you can too! If you see a video not have the sponsorblock added, please contribute if it needs it!
It's fantastic at what it does and I cannot recommend it any further than the highest praise. Make sure to check out this developer's work. Very smart, very helpful and very user-friendly!

10 months later:
It seems I cannot mark a full video as "Unpaid/Self Promotion" without it going away upon refresh. This extension was phenomenal before, it can be again.

I can't watch Youtube videos without this extension alongside Ublock Origin for blocking Youtube ads for free and Return YouTube Dislike for identifying bad videos.

Inadequate developer.

This extension helped me reclaim many hours of my life.

YouTube is unusable without it.

Works great for sponsors, tangents, unpaid promos, and the highlight feature is such a timesaver