Skype
Freemium
Skype is an instant messaging and VOIP (Voice Over Internet Protocol) client to communicate with people in a distant place.
Telegram
Free
Telegram is a free cloud-based instant messaging platform.
IM+
Freemium
IM+ supports simultaneously major IM services, including Google Talk, Twitter DMs, Yahoo!, AIM/iChat, ICQ, Jabber (and Slack through Jabber), etc.
LINE
Freemium
LINE is a new communication app which allows you to make free voice calls and send free messages whenever and wherever you are.
ChatSecure
Open Source
ChatSecure is a messaging application for iOS which allows OTR and OMEMO encryption for the XMPP protocol.
Hangouts
Free
Hangouts is an instant messaging software developed by Google.
TeamSpeak
Freemium
TeamSpeak is software for quality voice communication via the Internet.
Linphone
Open Source
Linphone is a free voice over IP (VoIP) service and SIP client.
FaceTime
Freemium
FaceTime is a proprietary videotelephony product developed by Apple Inc. FaceTime Audio is an audio-only version.
Wickr
Free
Wickr is an instant messenger application.
