Edward Snowden-endorsed developer Open Whisper Systems has announced the first public beta of Signal Desktop, a secure chat app for Chrome.

The new release enables users of its popular mobile app, Signal Private Messenger, to carry on a conversation across even more devices.

One notable issue with the initial build is it only connects to Android devices, although iOS support is expected in a future release.

As with the mobile version, Signal Desktop is a free app for secure one-to-one or group chats on mobile phones, avoiding SMS fees, and with support for file attachments and media sharing.

Signal Private Messenger hits the desktop

That’s nothing unusual, but Signal’s major plus point is its security. End-to-end encryption protects everything you’re doing from snoopers, even Signal’s server doesn’t have access to your communications, and the app is open-source so technical users can review the code to check what’s going on.

The technology is impressive, and endorsements by Bruce Schneier (“I am regularly impressed with the thought and care put into both the security and the usability of this app. It’s my first choice for an encrypted conversation”) and Edward Snowden (“Use anything by Open Whisper Systems”) don’t hurt, either.

Signal Desktop beta is an open-source secure chat app for Chrome.