Yo!  Sup?   Whoops.  I said "Sup".  that was too much, at least when you post something through this app.   Sup with dat? 

I kid you not.  The app is called "Yo".  You download it (for free, by the way).  You find someone on your contact list and you send the word --ahh - YO!   I'm not sure if you need further explanation, but in case, here's a better description from Newsy.com

Now I downloaded the app, and something made me extremely uncomfortable. It asks for your phone number "to find your friends and allow them to find you".  It says that the contacts are not stored anywhere and only be used to find your friends".

Well, I'm not so sure about that, because according to Time.com, the app allegedly got hacked by college students and they could access anybody's phone number because of it (including the owner's).

They are working on the problem as we speak, and I'm sure it will be fixed in case you want to use it, but let the buyer beware (even though you didn't pay anything for it)

I just find the whole thing hysterical, yet fascinating at the same time. Fascinating in that they raised $1 Meeeeeeeeelioin dollars so far and it's actually getting rave reviews, so here's the link if you want to try it out.  For me, I say "NO".

Yo, the app.