WebCEO has been my personal favourite application when it comes to search engine optimization. I have used the pro version for a number of years to improve site ranking. The personal version, which is free to download allows keyword researching, site optimisation and suggestions to improve your sites ranking. A properly optimised site could mean more traffic, increased relevancy and better business if done properly.
: I would advise reading the guide before using this software. Although you may feel tempted to use the submit to search engines tab, Ive seen sites disappear from search engines when users failed to understand that hitting submit every single day would NOT get the search engines to crawl their site faster and led to banning. So be warned