A few options mentioned by the community are worth considering.

Craft & Vision publishes photography ebooks directly as PDFs, and these can be imported into the Kindle app for syncing across devices. Their books are generally focused on photographic technique and creative topics, so they can work well if you want instructional reading that isn’t entirely dependent on large printed images.

Kelby training books were also recommended. These are more oriented toward the basics of digital photography, and they are typically available as PDFs rather than native Kindle editions.

For a specific title, The Photographer’s Eye was recommended for its strong focus on composition and useful examples. Because it is partly visual, the reading experience may depend on your screen size, but it’s a solid choice if composition is your main interest.

In general, for e-readers, text-heavy photography books such as technique, memoir, and composition guides tend to translate better than image-driven coffee-table books.