Signal is a messaging app that's available for iOS and Android devices. Like the best messaging apps, it supports cross-platform text, voice and video chats.

But Signal can have group chats with up to 1,000 people. Signal is free to download in the Apple App Store for iPhone and available for Android devices on the Google Play Store.

A cybersecurity expert explains what features to look for when choosing a secure messaging app amid White House controversy over Yemen attack plans.

Signal, Telegram, and WhatsApp provide cross-platform encrypted communication regardless of whether users operate on iOS or Android. However, security vulnerabilities extend beyond the apps ...

Until recent news involving the Signal app, it was a relatively unknown messaging app compared with WhatsApp to many nontechnical users.