I have been using Rytr for nearly one month and I've been impressed with the quality of the AI Content Writer.
It has a simple interface that includes a pop-up too bar/ribbon with commands that makes it very intuitive and easy to use.

It's still early for this app and they're adding features regularly ,eg. magic command use case.

I have the $39 lifetime Appsumo deal which includes 50K credits free per month but also includes a 30% discount coupon that can be redeemed against the monthly unlimited credits level for Rytr.

This a great tool for those who struggle with content writing looking for an affordable solution.