Yes there are quite a few on the market. Most of them are very good - but some do have a small learning curve attached to learning them. It really depends on exactly what you are wanting to do with your comment poster, are you happy to spend lots of time mastering all the all the ins and outs or do you just want to click and go.
If you want to click and go you might want to check out NHSEO. This is a very easy program to use and rewquires minimal setup, load comments, urls, rss feeds etc. Then you just click and it'll auto post for you until you stop it. There are lots of controls that you can use to fine tune your posting eg post 50 links a day etc plus more.
It also posts to over 55 platforms I think so you get quite a diversity of backlinks from blog comments to trackbacks, guestbooks, image comments and lots more. Not only that but this software is under active development with updates coming out nearly daily + lots of useful support via an active forum, videos and email support.
I hope this helps.