WhatsApp, Telegram, Hike Messenger, Signal, Kik, Skype, Talkatone, Google Voice, Mattermost, WeChat, Tango, TeamSpeak, ICQ, Camfrog, Xabber, Tox, SiskinIM, Messenger Lite, RebTel, fcall.in, Dasher Messenger, Zulip, XendApp, Windows Live Messenger, MyChat, Graph Messenger, Chatzy, magicApp, Google Voice and Video Chat, KakaoTalk, AChatRoom, CloudTalk.io, ARKNet, ePhone, Mobilevoip, Teleport.Video, mjoy, Onoff, Phoner Second Phone Number, monocles chat, Nimbuzz, Honk, VIPole Secure Messenger, Conversations, glide.me, Tinychat, BlackBerry Messenger, Toky, JusTalk, Libon, Fring, BobRTC, ringID, Nextcloud Talk, Proficonf, Silent Phone, ToTok, Lifesize Video Conferencing, Yolla, AtomJump.com, Zalo, Tinode, ooVoo, Say Hi!, YeeCall, Bettergram Messenger, workshopX, WowApp, Talkonaut, Skype Lite, IGram, Voxeet, UppTalk, Pickapp, Starleaf, Video Web Call, Quickchat, Qute Messenger, Bleep, Isotoxin, HipChat, VK Me, STAGE by vr-on, WWChat, Kindaba, Video4sure, Peerio, SSuite UltraCam Video Phone, OpenWhatsapp, AVAILO, Dingaling, Tribe Messaging, IveTime, Convoz, Jongla, Comfi App, QuickMSG, Hemlis, Indoona, Photo4Tune, QuickCall.com, Hiboo, Subrosa, Talkray, Numbertank, Spotbros, PingPal Messenger, MyENIGMA, BlackBerry Messenger Enterprise, Lemon Group Messenger, EonPhone, forfone, Secret Messenger, Decoy Digits, QUGO, Gaption, SliQ, Yabb Messenger, Vidii, 3veta, GAM Messenger, SeaFour.club, Fuse Chat are some alternatives to Viber.