Just as a quick correction, Hangouts is not being discontinued. Google is appropriating Hangouts to be for Businesses. As sad as it makes me that they're doing that, it was never that popular with regular people, just businesses, and so Google's moved on to different messaging services for regular people. All new features and decisions for Hangouts will be made with businesses in mind. (Also, they might be splitting the video calling and messaging portions into two separate things, as per Google's new weird mantra, they're already testing that on mobile)
Also, a stable link for that seems pretty cool!