Expressions is an easy to use, functional and also very nice looking regex tester. No more fiddly web versions ;-)
(...) It's a sumptuous, minimalistic, don't-make-me-think app I use to evaluate regular expressions (regex).(...) Expressions the most Mac-like of any of the regex apps I've used. In fact, after I close Expressions and go back to my Mac's desktop, my desktop feels a little shabby.(...)
Expressions is a definitely great tool for regex. It’s so simple, elegant and gorgeous that I don’t want to use any other else.
Expressions by @apptorium is one of my favorite apps. It replaced my need to go on the web and search for online regex testers. Downloaded it from @setapp