In case you were unaware, The XKit Guy left Tumblr and that’s why the extension that has made tumbr more accessible to many of us has gone un-updated.
In his absence, a new fork of XKit has popped up ( Chrome || Firefox || their blog )
What does this mean? It’s a new version of XKit, using the same base code as the original XKit (meaning all of your favorite extensions are still there and are actually being updated (I believe XCloud is the only one that’s going un-updated because of the amount of work that it’ll take to replicate the XCloud server.).
I’ve made the switch to New XKit on my blogs and so far I’ve not had any problems. They’ve updated any glitches and have also made several tweaks to address recent tumblr tweaks (like the randomly bolded url and the reblogging issue). In other words, this is an actively updating version of XKit.
They encourage questions, comments, concerns, additional help with the coding as well as submissions of what your problems are so they can accurately adjust the code of the extensions to ensure they work properly.
If you’ve enjoyed having XKit, give this new fork a chance (and maybe pop over to new-xkit-extension and tell the amazing people who’ve taken up the challenge of making up for the shortcomings of tumblr that they’re doing a great job).