WhatsApp is a free messenger for chatting with your friends via the Internet.
At the moment, the number of users WhatsApp is more than 1 billion. By using WhatsApp you can send free messages to your friends from any city or country. You will only pay for the use of the Internet (Internet traffic flow). Messages are sent instantly and securely encrypted.
Telegram is a free messenger for sending text messages and multimedia files of various formats via secure channels.
Unlike the analogues, in a Telegram to the connection channel is encrypted securely, due to a completely new technology MTProto, which uses the several encryption protocols. In addition, this messenger sends messages instantly.
Viberis a popular VoIP application, designed to connect people between each other from all over the world.
Using Viber, you will be able to exchange messages, video and photos via a Wi-Fi network or 3G, as well as calls to your friends, wherever you want, even to another country, and it is completely free. At the moment, this program has more than 650 million users from all around the world.
Discord is a free software for communicating by text and voice messages via Internet or local network.
Initially the software was developed for gamers. The direct analogues of Discord are Skype and TeamSpeak. The distinction is that discord offers high performance and wide functionality. You can create a voice conference, as well as public / private chats, where you can communicate with an unlimited number of users.
TeamSpeak is a free software for voice communication with a group of people through a local network or the Internet.
TeamSpeak is working on VoIP technology (IP-telephony). In contrast to mobile or landline phone, you can talk to an unlimited number of people. The main advantage of the Team Speak is a high-quality connection with minimum delays.