Nowadays, messaging applications are growing fast. They've become more popular than social networks and more convenient for their users. Facebook Messenger, for example, is growing faster than Facebook itself. Telegram has only been around for about three years, but already has more than 100 million users. And that's just a start. Messengers are convenient, they provide a lighter interface than websites or mobile applications, and they do not inundate their users with unsolicited information. Moreover, messengers functionalities have recently been extended to support human-machine communication thus providing a whole new range of potential services.