In addition, you can set a timer to indicate how much time your friend has to read what you wrote. Once time's up, it will disappear, much like Snaps. It's not perfect -- the recipient can still screencap your conversation -- but that goes for all ephemeral messaging apps. Since it can be a pain to deal with messages that can only be accessed on a single device, though, the feature is completely optional, confirming The Guardian's report of an opt-in encryption feature for Messenger back in May.

Unfortunately, secret messaging doesn't support rich content like GIFs or videos. But then again, we imagine you're much less protective of your meme collection than, say, your credit card or bank account details. The experimental feature uses a protocol developed by Open Whisper Systems, which Facebook also used for WhatsApp's encryption. It's the same technology Google is using for Allo's Incognito Mode and the same one that's powering Snowden's favorite messaging app Signal. While it's only available to a very small number of users at this point, the company promises to make secret messaging "more widely available this summer."