Facebook E2EE
As discussed in the Tip of the Night for December 10, 2010, Facebook Messenger can be set to use end-to-end encryption. Follow these steps to enable E2EE in Messenger, which is only available on iPhones and Android devices.
1. In Facebook Messenger after clicking on the pen and pad icon to begin a new message, tap 'Secret' in the upper right corner.

2. The new message will include a caption indicating that end-to-end encryption is enabled.

3. At the left you'll be able to click on a clock icon which will set any messages you send to disappear at a set time interval.
