The Associated Press
--Year founded: 2009.
--Company founders: Former Yahoo engineers Jan Koum (the current CEO) and Brian Acton.
--Headquarters: Mountain View, Calif.
--Number of employees: 55.
HOW IT WORKS:
--Download the app to phones running Android and iPhones, as well as BlackBerry, Windows and Nokia phones.
--Messages are sent over the Internet, to individual people or groups.
--One check mark next to a message means it's been delivered; two check marks means it's been seen.
--Price users pay for one year of service: 99 cents.
--Number of monthly WhatsApp users: 450 million.
--Number of people who use Facebook's mobile products, including Facebook Messenger and Instagram every month: nearly 950 million.
--Number of WhatsApp texts sent per day: 19 billion; texts received on the service per day: 34 billion.
--Number of daily voice messages sent with WhatsApp: 200 million; daily video messages: 100 million; daily photos: 600 million.
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