Signal
Signal uses the Open Whisper System protocol, considered by experts to be the gold standard of end-to-end encryption. The app is one of the most popular secure messaging platforms — famed NSA whistleblower Edward Snowden is one of Signal's biggest advocates.
In addition to making secure calls and texts, Signal lets you send self-destructing messages that vanish after a certain amount of time.
It's free on iOS and Android devices and you can also download Signal's desktop app. To register, all you need to do is enter your phone number.
WhatsApp, the messaging app that Facebook purchased for $19 billion in 2014, has had end-to-end encryption since 2016. Facebook Messenger, it should be noted, does not have end-to-end encryption.
But the future of WhatsApp's encryption, which uses Signal's Open Whisper Systems protocol, is uncertain. Jan Koum, one of WhatsApp's founders, recently left his role at Facebook over concerns that the social network planned to weaken the app's encryption, reported the Washington Post.
iMessage
Apple end-to-end encrypts all of your conversations in iMessage, the default texting app on iOS devices. And iMessage even comes pre-loaded on Apple's Macs. But it only works if both people are using iMessage (sorry, Android users and Windows fans).
Confide
Confide uses end-to-end encryption, but the app takes another step in protecting privacy: every message automatically disappears after someone reads it, and the app prevents users from taking screenshots.
The app has become popular in political circles, and White House staffers are said to frequently use the app to leak to reporters.
Telegram
Telegram allows users to send end-to-end encrypted and disappearing messages. But be careful, your messages won't be secure until you turn on the "secret chats" feature within the app.
Telegram has also drawn criticism over the years: ISIS has reportedly used the app to spread propaganda and communicate privately. At the same time, Telegram has also been banned by the governments of Iran and Russia, which aren't too keen on the fact that the app allows secure communications.
Wickr
Wickr isn't as established as Signal or Telegram, but it bills itself as a solution for businesses looking for some extra security. If a company pays $25 per user per month for the Wickr Pro service, the app supports encrypted group video cals — something none of the others can do.
