VoxAxis

VoxAxis turns printed paper into audio on an iPhone. Point the camera at a book, a textbook, a stack of handouts or your own notes, and scan the pages one after another. VoxAxis runs OCR on each page, merges the scanned pages into a single document, and reads the whole thing aloud in a natural voice, from the first page to the last.

It is built around the whole job rather than one step of it. Scanning, text recognition, merging and playback all happen in the same app, so there is no exporting text out of an OCR app and pasting it into a separate reader.

Besides the camera it opens PDF, EPUB, Word, Markdown, RTF and plain text, and it can fetch free public domain books directly from Project Gutenberg, Wikisource and Aozora Bunko.

Other things it does:

Handles vertical Japanese text and multi column layouts. When reading a PDF it leaves out headers, footers, page numbers, figures and tables. Runs OCR on scanned PDFs that carry no text layer. Keeps the playback position for every document separately. Has a pronunciation dictionary, so a name or a technical term only needs correcting once. Lets you set the speed and the voice. Has display settings for dyslexic readers, including letter spacing, line height and type size. Has tags and folders, a share sheet extension, a home screen widget, and backup to your own iCloud account. Runs in English, Japanese, Korean, Traditional Chinese, German, French, Italian, Spanish, Portuguese and Russian.

The free tier covers a weekly allowance of listening time and scanned pages. A one time purchase or a subscription raises or removes those limits. Every tier has the same features.