It's only taken me a year to figure out how to see TSM (Google Plus) friends in RR3 on Android. I've seen TSM (and Team) friends in races but my friends list in the lefthand pull-out menu and the friends tab in TT results has always been empty. :(

Short of taking my phone apart I went through every game feature. Finally, found the answer in the games Achievements screen. At the bottom of the page there's a gamepad icon. That takes me to a screen (I think outside of the game) connected with Google's Play Games app.

There I noticed two options that were disabled. One to share my profile and t'other to view other peep's profiles. All I had to do was activate both and select who I want to see/share with. Having a RR3 circle in my G+ account I simply selected it for both options. Voila, RR3 is now plastered with all my friends. :)

Also, I'm adding a warning! Going through the game's options I noticed Data Usage was turned on. I've never activated it knowingly and often check it is off after every update. I can only assume that yesterday's hotfix turned it on or that by activating TSM profile sharing it automatically switch on.

Something to keep our eyes on.