Interesting look at Google's deal with RingCentral. It involves WebRTC to power voice and video calls through the Google for Work productivity suite.
Dialpad is Craig Walker's latest venture. It was formerly known as Switch.co before Walker bought the rights to the name and domain for dialpad back from Yahoo. He was an investor in Dialpad which sold to Yahoo in 2005. Walker was also the co-founder of Grand Central that Google acquired in 2007. It became Google Voice in 2009. Now Google is trying to revive Google Voice - and Walker is trying to revive Dialpad.
I actually didn't know about Jotspot or Springboard or Google Sites (slide 8). Interesting concept that they should market better.
BTW, Google Voice now has a separate mobile app from Hangouts. See more here.