I can help with a translation to Brazilian Portuguese (if you want that)!
One Improvement is a box to select if you want case sensitive or not (default is not).
Another is more beautiful regular expressions like group words in quotes ("", like in a Google search).
One more interesting thing is a number operator like '\#' that cam be used in the regular expressions to count the number of attachments.
For example:
Some one white:
"Helo! Here is 4 photos of mine party"
But there is only 3 attachments. A regular expression like '\#+pictures' resolves that problem.
Another idea is put synonyms, another text box that you group synonyms in ';' and separate with ','.
Ex: pictures,images,photos;files,folders;...
Thanks, and good project.