Edward Snowden - the whistleblower who is now in hiding after he leaked classified information, particularly about the National Security Agency's surveillance program - has endorsed Open Whisper System's Signal app in a Twitter post. It is purportedly the safest available messaging and would shield users from the prying and spying eyes of both the government and hackers. It is now available for download on Android.

Technically, Signal is no longer new, as it is based on Open Whisper System's two apps called TextSecure and Redphone. The company merely combined its features: the former lets users send messages securely, while the latter does the same for phone calls, according to NBC News. With Signal, users would be able to do both in one application. The app also does not contain advertisements.

Signal's setup process is straightforward. Once a user downloads it from the Google Play Store, he or she could immediately use it without creating an account. Sending a message is both safe and secure as long as the reciever also has the application installed.

Snowden has praised the application, citing that he uses it every day. Whisper System sought to underscore this point as it introduces the app to Android users. "We cannot hear your conversations or see your messages, and no one else can either. Everything in Signal is always end-to-end encrypted, and painstakingly engineered in order to keep your communication safe," the company said in an International Business Times report.

While Signal was launched on Android Monday, it has been available in iOS since last year. It is free in both platforms.