RegEx+

... but the usability (at least on macOS) is not good. It doesn't automatically update to show if your pattern matches. You have to click on "Options" or somewhere else in the UI to make it update. Sometimes it simply doesn't update or show your pattern at all, even though it is correct. This makes it not at all useful in trying to find the regex you need. It's rather frustrating.

Very bad

But it works and works pretty decent. Major buy though: pressing ‘return’ crashes the app when typing in the ‘evaluation text’ area. I lost my regex like that :( Pasting a value in with new lines works fine though. Another bug is that if your regex is line enough to wrap to the next line, when you delete someone at the start of it, making it short enough to unwrap back into a single line, the cursor moves to the end of the regex and you start removing characters from the end instead of where your cursor was initially

This is a beta of a decent app. The UI is clunky and unpredictable. For one example, tapping the "New" ("+") button gives you a different template every time for the first several presses, then gives blank entries. This is crazy design. The templates are fine, but that's not how to discover them. Also, there's no easy way to get back to your expression after pressing the "cheatsheat" button (which looks like a "magic" button; I had hoped that it led to a "regex constructor" feature). It also took me a bit to discover that "match"=red text, as there's no text that *dossnt* match in the templates Not worth paying money for, and really not yet good enough to be on the app store. But it has potential; I especially like that it's Mac-compatible with built-in syncing (though I haven't tested this feature).