I have written about this in the about & credits pagr. I have also spoken to the author of rubular.
FWIW I find your light design inspired by rubular to be visually superior. The community feature is great however I assumed from the name that it would just be a forum, perhaps a different label would help show its utility - maybe "favourite regex"?
Glad you like the design :). Hmm, something like "Regex library" maybe? Unsure of how to word it properly.