Jan Koum and Brian Acton founded WhatsApp in 2009 after they left their job at Yahoo!. Jan Koum bought an iPhone in January 2009 and soon realised the app industry’s potential on a few months old App Store.
He wanted to build an app that shows statuses next to the individual names of the users. Koum discussed the idea with Acton, and both started visiting Alex Fishman for more insights.
But executing this idea was impossible without the help of an iOS developer. So, Alex introduced them to a Russian developer, Igor Solomennikov, whom he found on RentACoder.com.
Koum named the app WhatsApp to sound like "what's up". On Feb 24, 2009, he incorporated WhatsApp Inc. in California. However, when early versions of WhatsApp kept crashing, Koum considered giving up and looking for a new job. Acton encouraged him to wait for a "few more months".