LinkedIn announced that it is open sourcing its WhereHows data discovery and lineage portal. WhereHows is made up of a data repository to store metadata content, a web server that surfaces the data through a UI and an API, and a backend server that periodically fetches metadata from other systems. http://archive.devwebproit.com/2016/0308.html
There are a TON of SEO specific tool extensions that exist already. And most of them do the same thing as the others. However, when it comes to working online nothing can make your job easier than plugins/addons for your browser to help speed things along outside of the routine SEO toolbars.