All you need to know about WhatsApp messenger

Facebook Inc will buy the fast-growing mobile-messaging startup WhatsApp for $19 billion in cash and stock in a landmark deal. Here's is some key information about the messenger -

FOUNDED IN:
2009.

FOUNDERS:
Former Yahoo engineers Jan Koum (the current CEO) and Brian Acton.

HEADQUARTERS:
Mountain View, California

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.

VITAL STATS:
-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.