Facebook's Messenger has more than 1 billion users, the social media company said on Wednesday, making it one the world's top three apps. This figure comes just two years after Messenger was split off from Facebook's main app. Facebook now owns three apps with more than 1 billion users, and has the chance to make more money from advertisers. Its main Facebook app is the most popular, with 1.5 billion monthly active users, followed by Messenger and WhatsApp.

The closest rivals in app charts are Google Maps and YouTube.

Facebook's Instagram is also quickly gaining users, reporting last month that it had more than 500 million app users.

Facebook has been trying to make Messenger an integral part of its business, by building chatbots - computer programs designed to simulate an intelligent conversation - inside the app, allowing business customers to message users directly.

It has also launched a digital assistant, M, to some users in the San Francisco Bay Area that can help with tasks such as sending flowers.

Facebook said more than 1 billion messages are sent between people and businesses each month on Messenger, a number that has more than doubled over the past year, and that 18,000 chatbots have launched on Messenger.