BitTorrent has updated and officially launched Bleep, its secure messaging service, bringing it to iOS and adding a Snapchat-a-like "whisper" function that makes messages self-destruct shortly after they're sent. Today's update means the app, which allows users to make free voice calls and stores encryption keys for messages on users' devices rather than in a hackable repository, is now available on Android, Windows, and Mac, in addition to iOS devices.

When the new whisper mode is selected, pictures or text sent to another user will disappear 25 seconds after being sent. While users have got past similar Snapchat restrictions by simply taking screenshots of sent messages, Bleep offers some protection against this tactic: when reading messages from a contact, their username is blocked out. If you want to see who you're talking to, you'll need to press an eye icon that in turn blurs the entire message history, ensuring that users can't be easily tied to potentially incriminating screenshots.

The torrent company first launched the messaging app in pre-alpha form for Windows last July, before expanding it to Android and Mac in September. From its birth, Bleep has been one of the few messaging services that doesn't require personal information to set up an account — while you can add mobile numbers or email addresses to help your friends find you if they start using the service, the only information you need to enter to use the app is a nickname. Users can also be found using specific Bleep keys.

While other messaging apps have bigger userbases, a larger suite of functions, and a wider range of stickers, few are as secure as Bleep. Where most chat services send messages through the servers of the company that created them, leaving metadata behind as they travel, BitTorrent's app sends communications directly between users. The company says it would be "practically impossible to figure out who is talking to who at what time," an appealing feature in an age when naked pictures, work emails, and phone records are secretly harvested by shadowy third parties.