What are some tools that would aid in content writing ?

Here are some of my favorite tools:

Grammarly

I love how it helps correct my sentences with proper grammar, as English is not my first language.

Copyscape

I use this to check if my work is originally written to avoid problems with duplicate content.

RankMath or YoastSEO for Wordpress

This is a plugin for Wordpress that helps me know if my content is "SEO friendly". It basically tells me if my keywords are sufficient in the content, and if the length (as well as other criteria for good SEO) is met.