I just discovered that Grammarly, the company behind the popular AI-powered spelling and grammar checker of the same name, has an iOS keyboard that finds spelling mistakes and grammatical errors and helps you fix them on the fly.

This little utility is like having a personal editor wherever you go. As you write with it, the keyboard's built-in grammar checker scans the entirety of your text for common grammatical mistakes (like misused commas) and complex ones (like misplaced modifiers). Corrections are listed in a toolbar above the keyboard, and a simple tap on any correction inserts it for you. It'll even give an explanation of why it thinks something needs correcting. If it wants to correct a "misspelled" word you know is legit, you can add it to the keyboard's dictionary so it stops bugging you.

The keyboard is free to download from the iOS App Store.