Re: Closing the app when you are several screens deep
Well, the normal approach is to just return through your screens until you return from your entry point. Make each of the screen's functions return a special value that is checked by the caller, which then returns a special value to its caller, etc.
The stop statement will terminate your channel, but this is not a recommended approach. It makes your channel appear to have crashed. I don't think this actually has any detrimental effect right now but it's not recommended.