E.

I normally don't comment, but I was absolutely not on a wavelength with the constructor today. My tipping point for this puzzle was the cluing for 63A—how exactly does "Cellphone's weather app, e.g." equal WIDGET? A widget is not the same as an app. The app may *have* a widget that can be displayed on the home screen, but this is such a nonsensical clue to me. Seems like I'm the only one taking issue with it, though.