Remember, only MetroPCS, Sprint and TMobile phones with Rich Communications Services will be able to use this - it's not compatible with older phones, so you can't use the "advanced" parts to talk to anyone with an older phone until it's incorporated as an Android standard or someone comes out with a universal joyn app. Considering that Google seems set on using Hangouts as a standard, I think we'll have to wait for 3rd party apps. That still means that all the people you want to use it with will have to install an app (which they can do now - there are various other standards that do the same thing).