TomoTomo

Read the book or listen to it. Switch from where you left off. Ask the AI questions about what you're reading. Have it generate images.

This isn't a store and it isn't a subscription. If you already own the ebook and the audiobook, however you got them, TomoTomo just works with the files you have. No new library to buy into, no locking your books behind another app's account, no paying Amazon a second time for something you already paid for once.
What it does:

Reads your own EPUB and PDF files, full screen, nothing in your way
Plays your own M4B and MP3 folder audiobooks, with real lock screen controls
Pairs books to their audiobooks automatically, or manually if it guesses wrong
Highlights the narrated sentence as you read, with word highlighting and a reading window if you want them
Finds a passage in the text and jumps your spot to it
Lets you highlight and keep notes as you read
Asks an AI companion about your book, with spoiler-aware catch-ups
Generates illustrations from passages, and custom covers
Adjustable font, spacing, and five themes, including true black
Playback speed and a sleep timer, because obviously
Browses free public-domain books and audiobooks
Keeps your files on your device. Reading, listening, page scanning and audio alignment all work without a connection
Syncs your position, highlights and stats across your devices using an anonymous account. No email needed unless you choose to sign in
No ads, no analytics, no tracking

There's also an optional AI companion. Ask questions about the book you're reading, get caught up on the chapters so far, or talk through what just happened. You choose how much of the book it can see: just nearby text, everything up to where you are, or the whole book. Imagine turns a passage you're reading into an illustration, and you can generate a custom cover for any book or audiobook. Nothing is sent until you use one of these, and the app shows you what it will send first. Generated images stay on your device.

That's it. No gamification, no login wall, no upsell before you've even started reading, no renting access to books you've already bought. Just your books, staying in sync.