You don't need to pay for an Audible subscription to have your iPhone read books to you. By enabling an accessibility setting, you can make your iPhone read the text of whatever it is you have open, from a book in iBooks to an article you have open in Safari or another app. This setting is also available on iPads.
It's not a perfect replacement for Audible, though, since AI does the reading instead of an actual living, breathing human. You do have options, however, for the type of voice and language you'd like to hear. It could prove useful if you have poor eyesight or impaired vision, obviously, but it could also come in handy for times when you're just tired of staring at your iPhone screen, whether you are reading in a dark room and can't dim your screen enough, attempting to walk and read at the same time, or are getting jostled on the subway and can't keep your phone steady enough to read comfortably.
To enable the setting, head to Settings > General > Accessibility > Speech and toggle the switch on for Speak Screen.
With this setting enabled, you can swipe down with two fingers from the top edge of your screen and a voice will begin reading whatever text is on the screen. A small control panel appears that lets you pause the speaking voice, skip slightly forward and back, and speed up or slow down the speaking rate.
You can also ask Siri to start reading your iPhone out to you. Call up Siri by holding down the home button or by saying, "Hey, Siri" (if you have this feature enabled) and then give the command, "Speak screen."
In testing, the Speak Screen setting worked with both iBooks and Kindle apps. It began reading at the top of the current page and when it reached the end of the page, it turned to the next and kept reading. It also continued speaking with my iPhone locked with the screen off.
It also worked with Safari, Chrome and the Google search app, but the every word on the screen gets read, from headlines and bylines to photo captions and time stamps. I found the same to be true with the Huffington Post app, but not with NYTimes app. With the Times app, Speak Screen skipped the headline, byline and date stamp and started in at the beginning of the article.
If you want a different style speaking voice or another language altogether, head back to Settings > General > Accessibility > Speech and tap Voices to select among 27 languages, each of which offers a handful of voice styles.
I wouldn't want to listen to an entire novel in this manner, but I might use it for a chapter here and there. Or to get the news while giving my eyes a break.