Do you use TTS [text-to-speech]for audiobook experience? Which apps?

I'm trying to find a good Android app for Text-to-Speech synthesis, so I can turn eBooks into audio books. There are solutions on the Play store, but none are cheap, and I don't want to pay close to $100 before knowing its good, and trial periods are too short to decide. Obviously iOS apps are welcome too for anyone who might be interested.