Background in web, desktop helpful, but also possibly a hindrance.
Mobile apps are reactive, event based, multithreaded, often in the background.
Web form or Windows form really mostly waiting on the user, active,
Mobile apps are ADD, stop start, look at me, bored with you, got a call, power off, back to you, what's new?
Not just type and click,
touch-screen swipe, pinch, rotate,
Start-stop, I’m back – what’s new, hold-on got a call
Battery died, I plugged in, I’m ready for you now, but I’m playing music in the background, I hope that’s ok
On wifi, on cellular, Airplane mode or Upper Peninsula
Notification inbound, tripped a geofence, in a beacon region
Reactive programming, event-based, asynchronous
Much of code is written in the background