Yoast SEO is the most used and popular WordPress SEO plugin. If you're an SEO or online marketing professional using a site built in WordPress, Yoast SEO is a must-have plugin.
The plugin allows you to optimize your website's metadata (title tags, meta descriptions, meta keywords, etc.), instantly analyze page or post content, configure your robots.txt file, and a lot more.
Discover at: yoast.com/wordpress/plugins/seo/
Cost: $0 - $69