▁and ▁took ▁a ▁year ▁off , ▁travel ing ▁around ▁South ▁America ▁and ▁playing ▁ult imate ▁fr is be e . ▁Both ▁applied ▁to ▁work ▁at ▁Facebook , ▁and ▁both ▁were ▁rejected . ▁ ▁Wh ats App ▁and ▁Facebook ▁In ▁January ▁ 2 0 0 9 , ▁K ou m ▁bought ▁an ▁iPhone ▁and ▁realized ▁that ▁the ▁then ▁seven - month - old ▁App ▁Store ▁was ▁about ▁to ▁spawn ▁a ▁whole ▁new ▁industry ▁of ▁apps . ▁He ▁visited ▁his ▁friend ▁Alex ▁Fish man ▁and ▁the ▁two ▁talked ▁for ▁hours ▁about ▁K ou m ' s ▁idea ▁for ▁an ▁app ▁over ▁tea ▁at ▁Fish man ' s ▁kitchen ▁counter . ▁K ou m ▁almost ▁immediately ▁chose ▁the ▁name ▁Wh ats App ▁because ▁it ▁sound ed ▁like ▁" what ' s ▁up ", ▁and ▁a ▁week ▁later ▁on ▁his ▁birth day , ▁February ▁ 2 4 , ▁ 2 0 0 9 , ▁he ▁incorpor ated ▁Wh ats App ▁Inc . ▁in ▁California . ▁ ▁Wh ats App ▁was ▁initially ▁un pop ular , ▁but ▁its ▁fort unes ▁began ▁to ▁turn ▁after ▁Apple ▁added ▁push ▁notification ▁ability ▁to ▁apps ▁in ▁June ▁ 2 0 0 9 . ▁K ou m ▁changed ▁Wh ats App ▁to ▁" ping " ▁users ▁when ▁they ▁received ▁a ▁message , ▁and ▁soon ▁afterwards ▁he ▁and ▁Fish man ' s ▁Russian ▁friends ▁in ▁the ▁area ▁began ▁to ▁use ▁Wh ats App ▁as ▁a ▁mess aging ▁tool , ▁in ▁place ▁of ▁S MS . ▁The ▁app ▁gained ▁a ▁large ▁user ▁base , ▁and