I keep getting the message "why you no play candy crush"

[whatiswrong]

Hi, although I get the message on my iPad, I have seen other people get it on their iPhones and iPods.

Anyway, randomly I get this popup notification that says "<there is a long line of gibberish here> why you no play candy crush"

Is this a virus? If so, would restoring it to factory settings remove the virus? If not, how do I get this to stop?