WhatsApp (formerly known as WhatsApp Messenger) is an application that is a cross-platform messaging service, that is used to send text messages, make voice and video calls, send audio messages and share media content through an internet connection. WhatsApp is now owned by Facebook
The name WhatsApp is a play-on-words of the informal expression "What's up?", meaning "What's going on?", where the "up" part was substituted with "app", which is short for application.
The correct pronunciation of WhatsApp is a combination of the two words What's
. So when pronouncing WhatsApp you have to say one word immediately after the other, as heard in the audio pronunciation. However, be careful not to pronounce App