This is an odd one -- it's not a single application like the others on this list. Rather, it's a collection of free (ad-supported) tools to help you get your website recognized by search engines. In other words, these apps are search engine optimization tools. Examples include the Advanced Meta Tag Generator, which generates a list of meta tags based on information you provide about your site, formatted and ready to paste into your site's code, as well as the Keyword Typo Generator, which gives a list of likely human misspellings for your keywords so you can buy those, too. This set of tools will help you fine-tune your site for maximum performance. And did we mention they're free?