If you've tried using the Weasyl crossposter (waxpost) in the last couple years you've probably noticed it does not work anymore. Also, it was only available for Chrome. So, I've updated it into a userscript that can be used with any browser.
Right now it only works with Furaffinity, since that's all I use. But, if there is interest for this to work with other sites I can work on that.
Instructions to install are on this page.