In April, Google announced a groundbreaking technology that could allow Android users to use their smartphones as hardware security keys whenever logging into Google accounts on their laptops or work PCs. Today's news means that iPhone and iPad users can now use their (secondary) Android smartphones as a security key whenever logging into their Google accounts on an iOS device. To use it, users will have to have Bluetooth enabled on both their iOS and Android devices, so the Android smartphone can sign and authorize any login attempts for Google accounts initiated from the iOS counterpart. Because there's no actual Chrome browser on iOS (Chrome for iOS is actually running on WebKit -- aka a customized Safari), for iOS devices, the Chrome browser will be replaced by Google's Smart Lock app, which users will have to install on their iOS devices. If iOS users need help in setting up their Android smartphones as a security key for iOS devices, Google has some instructions in this blog post. Only Android smartphones running Android 7.0 (Nougat) or later support the built-in security key mechanism.