I'm still wrapping my head around the idea of a jazzed up book. Maybe I think small, but when it comes to fiction, the only sort of jazzing up I might like would be to be the agent of action in the story.
Can you say "text adventure?"
Everything else I might like-the extra maps, maybe a glossary and a character list, and any support material used in world--doesn't really need to be anything more than additional text material attached to the end & a hyperlink menu down the side to click through to this material should I want to reference it.
I was sitting with an iPad and an enchanting 3 year old boy t' other day, trying to read what might be considered an app book with him, but it just wasn't as much fun for him as simply snuggling up and reading a regular sort of book. He was off and away about 1/2 way through the story.
The thing about steamrollers is, they move pretty slow. It's easy to get out of their path and continue reading.