Since audiobook enthusiasts might be in this thread ... does anyone know of a product (outside Kindle Whispersync) that can ingest an audiobook and the corresponding e-book and using speech-to-text keep them roughly in sync so you can quickly go between the two?
https://github.com/readbeyond/aeneas can output SMIL e-books where each line of text is associated with the corresponding segment from the audiobook. But I don't know which e-book readers support that format.