Alright, but missing a few things

The interface is nice and clean and everything seems to work, but I have two complaints. First, its unclear whether Patterns assumes Posix or PCRE syntax. Second, in Match mode, it doesnt display groups. You can figure out the groups by switching to Replace and writing the appropriate replacement expression, but it would be great to display the groups in the regular Match mode, as well.

Good Thom about Patterns - The Regex App