I think this is overdue a proper announcement!
If you're unaware, I'm one of the members of the New XKit team. It's no secret though that New XKit is kinda dead in the water, thanks to Tumblr's overhaul of its interface which broke almost every feature we had. Oh, and everyone else on the team has a day job now, so I decided to take matters into my own hands:
XKit Rewritten is the result of my work of over a year, now available for Firefox and Chrome (and by extension, Edge and Opera too). There are still features to be added, but the featureset has now mostly overtaken the current working featureset of XKit 7.
If you're already an XKit user, I heartily recommend trying the new experience - even if it means configuring everything again - for its improved performance and increased compatibility.
If you're not already an XKit user, I invite you to give it a go! There's probably some option you'll enjoy. Even if you're on your phone all the time, there's a janky way to set it up on Firefox for Android (sorry, iOS users; blame Apple, not me) which I've also detailed on the wiki.