After the success of the Sushi joint, comes the app everyone is talking about. But what actually is YO? It seems odd to do an explainer piece on what may actually be the simplest app ever envisaged, designed or used.
What you do, and this is the genius part, is send the word "yo" to anyone else who has the app. As the introductory tour tells you, "want to say thinking of you? Send yo."
As you probably won't be too surprised to hear, Yo started out as an April Fools Day joke and has around 50,000 users. The design of the app is simple: no swiping no real navigation and no typing. Find a friend, touch the screen, Yo.
At the centre of the idea, as Tech Crunch points out, is that the one word can be taken differently depending on context. A YO from a friend when they arrived at the meeting you arranged is not the same as the YO you get when England score against Uraguay.
That for me is the beauty of it: we get so many emails and messages and pictures on our phones that all nuance has been removed from communication. Saying less might actually give us time to pause and think a bit more about what we're saying.
Or it might be a fad that blows over.