RegExr - RegExr.com is an online tool to learn, build, and test Regular Expressions.
What the Chef!? - Make your own recipe, just start with the ingredients.
Atomize by Quarkly - Library for creating atomic react components
Notepin - Extremely simple note-taking + blogging ✍️
RegEx Generator - RegEx Generator is a simple-to-use application that comes with the brilliance of intuitive regex and is also helping you out to test the regex.
regular expressions 101 - Extensive regex tester and debugger with highlighting for PHP, PCRE, Python and JavaScript.