The legality of several things is now under doubt. Previously, this app was taken down from the Google Play store, but it is now back up and running. The WhatsApp team was asked for explanation, but the answer was less than stellar. WhatsApp's developers dubbed it "illegal" and "unsafe," respectively. It's just that the officials aren't talking about it. As a result, the legality of a situation is ambiguous. A grey list app is one that is neither legal nor unlawful, as the name implies.