This is the tool I mainly use for my own SEO projects. It is a paid tool, but the free version has almost the same features, with the down-side that you cannot save your projects.
It is a suite of desktop tools with 4 extensions. The ones I use mostly are the Website Auditor (running SEO audits for my sites), Rank Tracker (to see how I do in Google for my saved keywords) and the Link assistant, to track backlinks for my site.
Instead of paying monthly, you only pay a limited one-time fee, so this software is very cost-efficient.
This is a paid tool, with a monthly fee, depending of the which features you need. But out of the many SEO tools that exist, this is probably the best there is.
You can always sign up for a free trial to test-drive the tools, see the link below:
Joomlaseo.com is fully built and written by Simon Kloostra, Joomla SEO Specialist and Webdesigner from the Netherlands. I have also published the Joomla 3 SEO & Performance SEO book. Next to that I also sometimes blog for companies like OStraining, TemplateMonster, SEMrush and others. On the monthly Joomla Community Magazine I have also published a few articles.
Joomlaseo.com is not affiliated with or endorsed by The Joomla! Project™. Use of the Joomla!® name, symbol, logo and related trademarks is permitted under a limited license granted by Open Source Matters, Inc.