Natural Reader has a free version but I like the voices and features available in the paid one. This app has supercharged my reading. I’ve read more books in the past year than in the preceding 20 years as a result of being able to convert any free pdf or text copy of a book I find, into audio format.

The app can even do optical character recognition of text from a phot and read it out. And the web plugin can read any webpage aloud. It’s a great app so I don’t mind placing some value in the premium version. But the app is great even without a subscription