There's a new app, maybe you've heard of it, Yo. No, seriously, that's the name of the app, Yo. As in, "Yo dawg." Yo does one thing, and one thing only: it sends a contact a notification of "Yo." No message attached to that, no images, no context, just "Yo from RENERITCHIE". It took eight hours to code, and yet somehow it's sweeping the globe in monosyllabic fashion, and even more inexplicably has raised a million dollars in funding to do… what? Hell if we know.