Twillio has been around for ages (since 2008!). I first came across it sometime around 2009 as a platform to send outbound SMS/Text messages and also to play with the inbound/outbound voice SDK too.
Twillio has moved on quite a bit and just to correct something in the podcast, Microsoft did not buy Twillio! instead, Twillio have raised a few rounds of funding. I have a feeling Microsoft expressed interest at some point, but I will check my facts!
Twillio now has a whole bunch of offerings, and not in the least very cheap inbound numbers that can be used for voice/text to name a couple. Right now, I have been using Twillio Studio to visually design workflows for incoming calls/texts in order to protect my own personal number/contacts.
Episode 9 - Twillio (Cloud Communications)