The issue with the CPS implementation here is that the compile times are too slow, and there are several restrictions due to flaws and limitations of the compiler. That's the reason CPS in the compiler is a big deal. I've used the CPS lib you're showing before, and it's very nice, but the compile times make it absolutely useless for productive development.
You can do Android with the C backend, but that's through some Java interop hackery, and there isn't anything in the ecosystem that would make Nim attractive for mobile development
It has Android support, but no wrappers for anything you'd actually want to do. Some successful Android builds of things like Raylib games with the Naylib wrapper exist, but nobody's really doing anything.
The mention of making CPS (continuous passing style) compiler integration possible is something very important. That would enable Go- or Kotlin-like coroutines to land in the language, which is sorely needed to end the async wars between stdlib's horrible asyncdispatch module, and Status.im's barely documented Chronos async/await implementation.