A Whatsapp App Page Is Seen On Facebook On A Samsung Galaxy S4 Phone
A Whatsapp App page is seen on Facebook on a Samsung Galaxy S4 phone in the central Bosnian town of Zenica, February 20, 2014. Facebook Inc will buy fast-growing mobile-messaging startup WhatsApp for $19 billion in cash and stock in a landmark deal that places the world's largest social network closer to the heart of mobile communications and may bring younger users into the fold. Reuters/Dado Ruvic

On Sunday Jan Koum the CEO and founder of WhatsApp tweeted that 600 million active users are using the social messaging app. It passed its 500 million mark in April this year and a 100 million more from December 2013.

Other messaging apps like WeChat claims to have 438 million active users, followed by Viber with 100 million and Tango with 70 million active users.

According to CNET the messaging app was acquired by the social networking giant Facebook in February for $ 19 billion. WhatsApp was launched by Jan Koum, Jose Torres and Brian Acton in 2009 with its headquarters in California.

Koum tweeted, "Now serving 600,000,000 monthly active users. Yes, active and registered are very different types of numbers".

The deal between WhatsApp and Facebook has received the approval of the Federal Trade Commission. To complete the acquisition, the social networking site still needs international regulatory approval.

Koum's announcement was on the basis of the number of people who use the app on a regular basis and not on the number of times the app is downloaded and installed on a Smartphone or tablet, CTV news reported.

WhatsApp has become the most popular social messaging app in the world with 600 million users sending monthly texts, emojis, images and videos. Followed by, WeChat that is mainly used in China with 438 million users.

According to CNET, when Facebook made the announcement to acquire WhatsApp, the social messaging app had nearly 450 million active users worldwide. The company declared in April that it hit half a billion users and people were using its service to share 700 million photos and 100 million videos on a daily basis.

Recently, Facebook forced its mobile users to download its messenger app. This decision was not received well by its users and critics worldwide. The Facebook messenger app was downloaded by 500 million users but people still do not prefer having multiple apps to access Facebook as it eats on storage space and permission to user's personal data. It is still unclear that Facebook is trying hard to push its messenger even after acquiring WhatsApp.

But, WhatsApp seems to be growing more popular than their competitors.