After all your work, it is a good thing to verify that you did a good job by SEO auditing your site. Especially if you only have 1 or a few sites, onPage.org is a tool I can absolutely recommend, as it gives you an extremely thorouh SEO audit for on-page SEO issues. Next to that, WebCEO.com offers a free plan that also includes a full on-page SEO verification, but with some off-site features as well, like ranktracking, social media tracking and Analytics integration.

Always remember that an automated check never replaces the human eye, but it can be a nice help. It actually does a nice job of finding any issues, not just for the homepage, but for the full site, allowing you to drill down on any issues:

You can also enter a few keywords that get tracked over time, plus quite a few more nice options. If you need more functionality or sites to monitor, you can sign up for a paid account. Similar tools are Moz.com and Raventools.com. For relatively small businesses WebCEO and Raven are probably the best choice. WebCEO is relatively the cheaper option, while Raven offers access to unlimited sites to track. Moz.com is a really good service, but relatively expensive for a restricted number of sites.

Other free SEO services

Other free tools, that require no registration are Seorch.eu and Seoworkers.com, but these require manual submission, and do not track over time

Also there are numerous addons for Firefox and Chrome that can be very usefull for your SEO efforts. One that I personally like a lot is the SEO Doctor addon for Firefox, as it constantly informs me of many parameters on every page:

Clicking on the window opens up more information: