Messages for Your Eyes Only
Do you ever feel like you’re being watched? With surveillance programs such as PRISM, you probably are. The App Store has many encrypted communications apps, and iMessage itself utilizes end-to-end encryption. But an app called Signal, may be the most secure option.
In fact, the encryption protocol—called the Signal Protocol—is an open source encryption option that is implemented in many communication software including Facebook Messenger and Skype.
The Signal Protocol is considered one of the most secure messaging protocols in the world. In fact, Edward Snowden has said he [uses it daily]. Users can set messages to expire, verify encryption using another communications method, and also make secure audio and video calls.
The app is available on Android, iOS, Linux, macOS, and Windows.