After the purchase of Instagram for $1 billion back in 2012, Facebook are now set to purchase the popular messaging app WhatsApp. The deal is said to be around $19 billion (£11.4 billion) spread in cash and shares.
"The purchase, $4 billion in cash plus $12 billion in Facebook shares and potential for an additional $3 billion in employee stock payouts, will see WhatsApp founder Jan Koum joining Facebook's board of directors". - MacRumors
WhatsApp is a free messaging app and now has more than 450 million monthly users due to the popularity of avoiding text message charges. WhatsApp claim that they are currently registering one million new users per day and currently stand as the 35th most popular app on the App Store.