Most book summary apps have a catalog. We don't.
I kept hitting the same wall building Summaia: the moment you commit to a catalog, you're in an editorial business. You're curating, licensing, maintaining. You're always one niche title away from "sorry, we don't have that one."
So we went the other direction — no catalog at all. You search any book, we generate the summary on demand. Choose the length (short, medium, long), choose the language, hit build. It's audio in seconds.
The interesting problem that unlocked was: now the product has to work for any book, every time. You can't hand-tune edge cases. The generation pipeline has to be good enough that someone asking for a 1987 management textbook gets the same quality as someone asking for Atomic Habits.
That constraint turned out to be the right one to build around. It forced a different kind of quality bar.
Still a lot to do, but the app is live on iOS and Android if anyone wants to poke at it.