On what date did Jan Koum incorporate WhatsApp Inc. in California?

Jan Koum incorporated WhatsApp Inc. in California on February 24, 2009. The company was created before the messaging service had become a global phenomenon, when Koum was still exploring what an iPhone application could do.

Koum had bought an iPhone in January 2009 and recognized the potential of Apple's relatively new App Store. He discussed an application idea with his friend Alex Fishman, initially imagining a tool that would show status information beside contacts, such as whether someone was working or on a call.

The app's early direction changed after Apple introduced push notifications in June 2009. WhatsApp could then alert users when a contact's status changed, and people began using those alerts as a primitive messaging system. WhatsApp 2.0 later added a dedicated messaging component.

A common mix-up is the difference between incorporation and launch. WhatsApp was incorporated in February, but its iPhone application appeared in the App Store in May 2009. The date also predates Brian Acton's formal arrival as a co-founder and his seed investment from former Yahoo colleagues.