Although there are a lot of cross-platform-development-solutions out there, most of them try to be universal and have a large focus. This makes them hard to expand and understand.
My hypothesis is, that it is possible, to create within useful period a own, very small but domain specific cross-platform-framework. The advantage would be that the developer will easiser get understanding of the target platforms and that the resulting product performs good due to the closeness to the underlying target platforms.