I'm using Realm on iOS at the moment for a reasonably large application. I originally had a C cross-platform core based on SQLite, but I found it too difficult to maintain and threw most of it out after attempting to make what should've been a minor change that ended up going on for two weeks.

Realm reduced the core size by approximately 90%, and while I've given up the cross-platform part (target platforms were iOS, OS X and Windows; obviously not focussed on Windows at this point), the code clarity and ease with which I can change data structures makes this approach so much better.

Are you guys looking at supporting Windows/C#/.NET at this stage, because while I don't develop much software for it, it does come up occasionally, and it would be good to use it throughout.