To a degree, associating an SEO tool’s success with it’s builder is a mistake — or rather, it’s a mistake to assume that the success and utility of one tool will have anything at all to do with the success and utility of any other tool, even one from the same company. There’s reason to have all of your tools come from the same company when you could just as easily (and often more effectively) cherry-pick the best tools from each company.

That said, it’s also a mistake to think that just because a company does SEO tools, it’s all they do. In fact, many of the most effective SEO tool companies also make apps, websites, and other software for other areas of Internet marketing and Web development, from PPC to website marketing.

It’s actually fairly accurate to say that the best SEO tools companies do more than just SEO tools, because the same understanding that they use to make SEO tools also allows them to make software for a variety of other purposes. More importantly, making tools for other purposes expands their comprehension of both their own code and the principles behind the market they’re writing for.

SEO tools companies can, do, and should also make software for:

• Social media management
• Pay per click management
• Link building
• Web design
• Hosting
• Website marketing
• App production
• SEO Content production
• Content marketing
• And dozens of other related areas

All of this is true for one simple reason: SEO tools companies are first and foremost software developers. They may have a pretty solid grasp on the principles of SEO — in fact, in most cases, they have a better grasp on SEO than the average entry-level guy working at an SEO company — but their real art is software development, and they should practice it in any SEO-related area that presents itself.

Ranking Checker by SEOmoz
For no cost, you can check your rankings for up to five keywords per day, and it keeps an excellent little log for you of how your keywords rank day after day — a log that you can download as a CSV file if you need. A dedicated SEOer can check about 150 keywords per month with this tool, provided you can deal with your updates being that rare.

MultiRankChecker by iWebtool.com
Sometimes, you just dont’ want to manually check the PR and Alexa rankings for your client and their seven major competitors all at once. Enter MultiRankChecker and you’ll get results in seconds.

Fiddler by Fiddlertool.com
Fiddler requires the .NET framework for Windows, so not everyone will be able to use it — but for those who can, it’s grand. Fiddler allows you to analyze all of the background communication that happens between a browser and the servers. It’s excellent for debugging a webpage that isn’t doing what you want it to in all of the browsers you want to do it in.

SEO Analyzer by Sitening.com
SEO Analyzer gives you a report that shows a detailed list of SEO components and how the assessed website stacks up to them. It’s not any substitute for a professional SEO assessment, but it’s a great tool for making sure that your website has the basics covered before you turn it over to the experts.

Backlink Checker by WeBuildPages.com
This is probably the best free backlink checker on the Web today, it’s simply a useful way to keep track of your backlinks, or, more importantly, analyze a competitor’s backlinks and see where they’re getting their juice from.

Are there more? Of course — probably hundreds of great free tools — but these are the ones that our SEO experts use on a daily basis. Try them out and see for yourself!