Here is one: http://spin.webeloper.com/ However, I do not encourage article spinning as the message you want to convey can turn out quite distorted especially with auto spinners. There are some out there that allow you to set your own keyword replacements however it is so much work that in the end you are better of writing another article. I've tried them both myself so thats just experience talking
Using software to automate a "distribution process" can hardly be called Black hat.. if people who automate things in their business in order to boost productivity are called black hatters then aren't we all? As defined on Wikipedia: Link cloaking, link farms, shady redirections, doorway pages, keyword, spyware/virus spreading, C--ky stuffing and such are all real black hat ... .. taking in consideration the nature of real black hat operations I would say article submissions (even if automated) can hardly be considered BH ... maybe a lighter shade of gray?
I'd highly suggest not using Article Spinners, it's one of the worst things ever and it can destroy your website :/
Oh,yes ,i think it is not a good method to promotion one's site,sometimes when we use rewrite software to write articles, it looks not well and some sentence we could not understand,it is not well for users. Thank you.
That's not the only thing you have to worry about, plagiarism comes into view, as well as the fact that most spinners turn your articles into unreadable gibbrish
Also remember that when you buy bulk package of articles from anyone in too cheap rates then do check it that if they are original or generated from article rewrite software . Because publishing such content in heavy quantity can harm you .
One of the ways to check this out is to use a similarity detection software known as Viper It just cross checks all articles in order to check if they've just been copy pasted with different titles.