When it comes to instant messaging, voice, and video calling app. Google has a portfolio of them; as if it were an investment and they needed to spread their risks. They got Duo (which now supports voice calls) Allo, Hangout, and Messenger. They all do more or less the same thing; either one or all of these functions; send an instant text or make voice/video calls.
However, Duo has an impressive trick up its sleeve. One that will make it an instant hit with the masses; had Google not baked a particularly exciting feature secretly. Now, that the word is out, it is probably going to be a hit.
Call anyone using Duo, whether they have it installed on their end or not
If you got Duo installed on your phone, you can call anyone on Android, whether they also have the app installed or not. That is all possible thanks to Google’s App Preview Messaging feature, which enables certain apps to be used to contact other users without them needing to install the app.
Like we said, this feature is possible through Google’s App Preview Click here to read entire article