Apple didn't pay Modern Family for them to use the iPad. MF asked Apple since they knew it was coming out and the script revolved around the dad being excited for a new product. Apparently Apple notoriously doesn't pay for product placement, though they do give products to use.
Anyways, I was just thinking since they literally talked to an Apple genius in the first Captain America movie, that maybe it's possible they got their hands on a new phone to use while filming. Marvel/Disney and Apple have always had close ties so I was just doing some fun speculation
re: working props, my boyfriend does prop styling and I've worked on a couple movie sets before, generally the tech props like that were working actual phones, though the screen is often rendered in.