I recently posted a preview of a Regex app I'm writing. It is not yet downloadable but could be soon. I'm eventually looking for some testers and maybe a sanity check as well. :-)
I'm primarily a Mac user but I use Windows too. The app with run multi-platform but perhaps initially Mac. So if you're a Mac user who reads this, I'd love to talk to you. The app just needs a few more tweaks for running under Windows - and I need to make it a little more robust before release in general.