App development workflow

I see. But it does not work on the emulator, does it?

Yes, it will do - but you have to have all the relevant parts installed in the emulator, which is a real pain. Definitely worth just using a real device for.

I get errors like "export" is not defined...

That's what happens when you upload an library and it tries to run the library as if it was an app. Generally I'd just issue load() in the LHS of the IDE right after, but if you're doing it a lot you can go to IDE settings -> communications -> Load after saving and change it to something other than 'load the just-uploaded file'.