I currently use WebCEO and Seorch, are there any free tools better than these for long-term data tracking / monitoring?
I am using Google Webmaster tools and Google analytics. I am using Google Webmaster tools as a SEO monitoring tool while Google Analytics as a data tracking tool. StatCounter is also a good data tracking tool. I have used it in the past for my client's site.
Use combination tools such as Google Webmaster & Analytics. Free tools will not give you proper details, as they have their restriction criteria.
For 'free seo tools', you can use some google tool like Google webmaster, Google analytics and also Google adwords for keyword planning. But free tool won't give you privileges all the time. You can use some premium tools like Majestic SEO
RankWatch launched its free website analysis tool, Website Review Tool, for all business owners. This is a very simple and easy to use tool - just type or copy your site url on the box and click on submit button, it will give you the brief regarding seo, social, mobile and technology details of your site. Test Your Website here- https://www.rankwatch.com/tools/web-analyzer.html