[misleading_name]

but it doesn't show what is matched - as in a example matched string - which is the most important thing

also how do you put in the case insensitive flag?

[Cyranix]

I think this would be quite valuable -- provide a second input for sample text and highlight the path taken. Bonus points for figuring out a way to handle multiple sample inputs, showing capturing group output, etc.

[pacaro]

Extending this idea, a regex (code)coverage tool would be great...