Ahrefs WT - Free access to site audit and explorer! [SEO tool]

So I just stumbled upon this tool from Ahrefs https://ahrefs.com/webmaster-tools. It gives you free limited access to Ahrefs Site Explorer & Site Audit which means that you can check your site for onsite SEO issues and monitor your backlinks for free.

Before today, I thought that I was well-versed in the different SEO tools out there, but for some reason, I had missed this one. Hope you will find it as useful as I do :)

While we are on the topic, do you know any other free and powerful SEO tools that you can recommend?