British writer and journalist Kate Riordan has penned Sanditon: Official ITV Tie-In Edition (£6), the novelisation of the show. It's available as a paperback, Kindle, or audiobook.
And for those of us who aren't familiar with what a novelisation is, it's a novel that adapts the story of a work created for another medium, such as a film, TV series, comic book, or video game. So in this case, it's a novel based on a TV show that's based on the original book by Jane Austen.