Article Spinner for Mac

I need either a web-based article spinning software OR one that is built on a Mac platform. The process would be: User submits unique article into software, then software highlights the words and word sets that should be changed. Then user goes to each word set to let the software to walk user through the syntax variations of words, sentences, and paragraphs. The software needs to provide syntax variations for word sets, sentence sets, and paragraph sets...with the understanding that human involvement is needed to make the software work most efficiently. Also, security measures if web based. This is needed out of necessity because I work off of a Mac...there is plenty of this software on the market that is PC based, but none of quality that is web or Mac based. I'll provide more details when requested.