The messaging app founded by Jan Koum and Brian Acton in 2009 was WhatsApp. The service began as a mobile status application before evolving into one of the world’s most widely used messaging platforms.
Koum incorporated WhatsApp Inc. in California on February 24, 2009, after buying an iPhone and recognizing the potential of Apple’s new App Store. He and Acton had previously worked together at Yahoo. The name “WhatsApp” was chosen because it sounded like the phrase “what’s up.”
The early app displayed users’ statuses, such as whether they were at work or on a call. Apple’s introduction of push notifications in June 2009 helped transform it into a messaging service, and WhatsApp 2.0 added a dedicated messaging component later that year. Acton joined formally after helping secure $250,000 in seed funding.
WhatsApp was acquired by Facebook in 2014 for approximately $19 billion. Signal is a common source of confusion because Acton later helped establish the Signal Foundation, but Signal was not the app he and Koum founded together in 2009.