I use and love Hangouts for this exact reason. I haven't found anything that can do the IM+Voice+SMS combo crossplatform. I don't get why Google isn't pressing

I use and love Hangouts for this exact reason. I haven't found anything that can do the IM+Voice+SMS combo crossplatform. I don't get why Google isn't pressing Hangouts hard vs. letting it languish. It really should be a core product that ties everything together. Unified contacts, instant communications of all varieties, whether SMS, IM, voice, video... Since it hasn't got an update in forever, the UI is crappy, and they've turned off all API access and denied people writing third party clients. I now wish there was an alternative, but I haven't found anything that does it all. Why, Google, Why!?!?