Duo works with your phonebook and makes it easy for you to make video calls to anyone in your contacts list. Video calls on Duo will be in HD formats but the app will adjust the resolution based on the available interned speeds. The app will also transition from cellular to Wi-Fi and will save your precious data if you happen to be in a known Wi-Fi zone while making calls on cellular data.
Duo offers end-to-end encryption of any data that you send or receive and will thus keep your calls private. While this is a great new addition, what's more convenient for users is the fact that Duo will switch between Wi-Fi and cellular connections without letting your calls drop. This way, you can initiate a call using your home Wi-Fi while leaving for work, use your cellular data on the way and finally connect to the Wi-Fi at work without suffering call drops.
Duo also comes with a new feature named Knock Knock which 'lets you see live video of your caller before you answer, giving you a sense of what they’re up to and why they want to chat. Knock Knock makes video calling more spontaneous and welcoming, helping you connect with the person before you even pick up.'
Duo isn't available to Android users in the UK as yet but will be in the coming days. So if you've missed FaceTime after switching from iOS to Android, Duo won't let you miss it anymore.