Speaking of WhatsApp, Parmy Olson wrote another piece for Forbes detailing the history of WhatsApp prior to the Facebook acquisition:
Koum almost immediately chose the name WhatsApp because it sounded like “what’s up,” and a week later on his birthday, Feb. 24, 2009, he incorporated WhatsApp Inc. in California. “He’s very thorough,” says Fishman. The app hadn’t even been written yet. Koum spent days creating the backend code to synch his app with any phone number in the world, poring over a Wikipedia entry that listed international dialing prefixes — he would spend many infuriating months updating it for the hundreds of regional nuances.
Early WhatsApp kept crashing or getting stuck, and when Fishman installed it on his phone, only a handful of the hundreds numbers on his address book – mostly local Russian friends – had also downloaded it. Over ribs at Tony Roma’s in San Jose, Fishman went over the problems and Koum took notes in one of the Soviet-era notebooks he’d brought over years before and saved for important projects.
The following month after a game of ultimate frisbee with Acton, Koum grudgingly admitted he should probably fold up and start looking for a job. Acton balked. “You’d be an idiot to quit now,” he said. “Give it a few more months.”