Re: 3D Touch messages..
I just heard Rene talk about how Apple populates the "who" on the Messages peek. He said that Apple uses an algorithm to determine things like your most recent text participants, your location and even time of day. The example that he used was that you always text your spouse at a specific time, Apple tries to make sure that if you peek on the Messages app at that time, that you spouse is in the list. Similarly, if you tend to text a friend from the local coffee shop in the afternoon, that it tries to make that person available when those factors are back in play.
Originally Posted by noaim
Sounds like pretty advanced stuff, and brings Arthur C Clark's 3rd law to mind: "Any sufficiently advanced technology is indistinguishable from magic".