( CNN ) -- WhatsApp , the globally popular texting app that Facebook just acquired for a whopping $ 19 billion , is adding phone calls to its list of services . At the Mobile World Congress in Barcelona , Spain , WhatsApp CEO Jan Koum said the voice service will be free and begin rolling out to users within the next few months . Currently , WhatsApp offers unlimited text and voice-mail messages between users . Its service is free for the first year , then costs 99 cents annually . `` We want to make sure people always have the ability to stay in touch with their friends and loved ones really affordably , '' Koum said in a speech at Mobile World Congress . As reported by multiple news outlets , Koum also announced that WhatsApp now has 465 million monthly users and 330 million daily users . The latter is 15 million more than what was made public last week when Facebook announced the purchase . Voice service will come first to Apple devices and Google 's Android operating system , with Windows phones and Blackberry to follow . The move puts WhatsApp in competition not only with other messaging apps that offer voice but chat tools such as Skype and even mobile carriers . WhatsApp 's unlimited texting has already helped establish it in places where smartphones and fancy data plans are less common . It has 40 million users in India and another 38 million in Brazil , two countries highly coveted by tech companies such as Facebook for their large populations and emerging mobile customer base . WhatsApp has n't released figures for the United States , where it is less popular . Last week , Facebook shocked the business world when it announced it was buying WhatsApp for up to $ 19 billion in cash and stock -- by far the social network 's largest acquisition to date .
Facebook bought popular texting service WhatsApp last week . WhatsApp adding voice calls to its messaging service . Comment: