Facebook's Instagram is testing a standalone messaging app called Direct, making it the company's third chat tool alongside WhatsApp and Messenger.

"With hundreds of millions of people using Instagram Direct, today we're announcing a test of a standalone Direct app. It's fast, visual and super fun. Only in six countries to start but can't wait for you all to try it." Instagram's vice president of product, Kevin Weil, said in a tweet.

The Instagram Direct app will be available starting Thursday on Android and iOS in Chile, Israel, Italy, Portugal, Turkey, and Uruguay.

When Facebook split Messenger from the main app, it drew an outcry from users. Today, the app has 1.3 billion monthly users - up from 500 million the year that it split - and yet its rating has risen to just three stars on iOS.