> What is the size of a minimal Fabulous app?

Agree this is interesting. Historically, Mono-applications on mobile was at least 10x bigger than Java application as they included the entire runtime system.

Can the runtime system be shared now? Is .NET Core a thing on mobile, and is the resulting download smaller?

While download size is no longer a problem for me, my guess is it is still a big problem many places in the world.