Accurate spelling and grammar are a hugely important part of making your content readable, and adding spellchecking and grammar checking to ReadablePro is high on our list of priorities.
We are, as of November 2018, testing our spellchecking software with a view to rolling out spellchecking in early 2019. Grammar is a bit more complicated, and we are experimenting with a few different options to bring you high quality grammar checking.
With all of our development efforts, we spend a lot of time on speed and performance. Good spellchecking and grammar checking are no good to you if they're too slow.
So, we appreciate your patience with the addition of these features, but please know that the time we are taking to get it right is for a good reason.