"click a picture of your friend and then contact them in any possible way using any enlisted app from there" First, I think this is a good idea. We already do

"click a picture of your friend and then contact them in any possible way using any enlisted app from there" First, I think this is a good idea. We already do this with documents on our computer. Sometimes we launch Photoshop first, but other times we right-click on a document first, and choose "Open With...", then pick an application. But I'd imagine third party developers wouldn't really like the idea of People equivalent of "Open With...", because that takes eyeballs away from their own contact list.