After Koum and Acton left Yahoo! Fishman found a Russian developer on RentACoder. Koum named the app “WhatsApp” to sound like “what’s up”. On February 24, , he incorporated WhatsApp Inc. However, because early versions of WhatsApp often crashed or got stuck at a particular point, Koum felt like giving up and looking for a new job, upon which Acton encouraged him to wait for a “few more months”. Koum changed WhatsApp so that when a user’s status is changed, everyone in the user’s network would be notified. Acton was still unemployed and managing another startup, and he decided to join the company. He officially joined on November 1. Koum then hired a friend who lived in Los Angeles, Chris Peiffer, to develop the BlackBerry version, which arrived two months later.