Koum chose the name "WhatsApp" and after several failures with the initial model, was ready to give up but Acton convinced him to stay.
After several attempts, WhatsApp was launched in the app store for iPhones in November 2009.
The Blackberry version of the app was released just 2 months later.
Facebook acquires WhatsApp in its biggest deal
Months after a venture capital financing of $1.5 billion, Facebook announced its acquisition of WhatsApp for $19 billion - its biggest ever deal till date.
Of the $19 billion, Facebook, advised by Allen & Co., paid $4 billion in cash, $12 billion in Facebook shares and $3 billion in restricted stock units granted to WhatsApp founders Jan Koum and Brian Acton.
In January 2015, WhatsApp announced the availability of WhatsApp web, a platform that mirrored WhatsApp on the web browser. Initially it was only available to Android, BlackBerry and Windows Phone users. Later on, it also added support for iOS, Nokia Series 40, and Nokia S60.
15 Nov 2016
WhatsApp video calling now available
WhatsApp has launched its video calling feature for all its users across iOS, Android and Windows; users can choose between voice and video calls when using the call feature.
The move sees WhatsApp catching up with a number of rivals, including Facebook Messenger, Skype, FaceTime, Viber, LINE and Duo.
In a statement WhatsApp said, "we want to make these features available to everyone."
03 Jan 2017
WhatsApp stops working on older iPhones, Android systems
WhatsApp has stopped working on older iPhones and Android systems; currently the app has stopped working on Android 2.1, 2.2, iPhone 3GS or iOS 6 and Windows Phone 7.
WhatsApp said anyone with older handsets should migrate to newer ones to continue availing the service.
It wants to ensure that it remains secure, some of which depends on the features of the newer operating-systems.
14 Feb 2017
Now, put 'stories' as your WhatsApp status
According to reports, WhatsApp, the popular messaging app owned by Facebook is working to update its Status feature under beta testing.
The new update will allow users of WhatsApp to upload pictures and videos as their status for a duration of 24 hours, after which they will automatically disappear, drawing a parallel to 'Snapchat stories.'
Privacy options will be included in the update.
17 Mar 2017
WhatsApp reintroduces text statuses
WhatsApp has brought back the text status feature after attracting flak for ripping off Snapchat's 'stories' feature.
Now, the text statuses have reappeared in the Android Beta version of WhatsApp in the about section of profiles. The status will roll-out to all platforms by next week.
Users can set a text status in the about section of their profile.
17 Apr 2017
WhatsApp to allow change of number, sharing live location
In a new feature found in WhatsApp's beta version 2.17.130, the company allows users to change their phone numbers and also share their live location.
It automatically notifies contacts and groups about the number change. Users can choose whether to share the new number or not.
The move will help users who lose chat data after changing numbers.