[txcwpalpha]

It's not just the apps that Google explicitly retires, there are also the ones that Google just stops paying attention to and they fade into nothingness. Google Voice comes to mind.

My company recently switched to Google suite of apps (Gmail, Hangouts, Calendar, etc) and soon after was given the heads up that we should expect minimal support/updates to Hangouts since Google is shifting their online chat efforts into Allo and Duo. We're now regretting that switch.