Skype is an instant messaging and VOIP (Voice Over Internet Protocol) client to communicate with people in a distant place.

Viber Free Messenger and Phone Calls.

LINE is a new communication app which allows you to make free voice calls and send free messages whenever and wherever you are.

BlackBerry Messenger, also known as BBM is an instant messenger and videotelephony application included on BlackBerry devices that allows messaging and voice …

Zello is an application for push-to-talk (PTT) walkie-talkie for consumers and business and available for Android, iOS, Blackberry, Windows Phone, Windows PC,…

WhatsApp Messenger is an instant messaging platform owned by Facebook.

Linphone is a free voice over IP (VoIP) service and SIP client.

KakaoTalk (Korean: 카카오톡), or sometimes KaTalk, is a free mobile instant messaging application for smartphones with free text and free call features.

Zoiper is an easy to use sip video softphone, with excellent voice quality and easy to setup.

Telzio is a cloud phone systems to power business voice, SMS, and fax services.