To play a match with your friends, tap on "New Game" in the Home,

Then select "Play with Friends"

There, you will see three options. The first one is "Make New Friends."

 This section will show you recently active friends and friends with similar skills. 

Then, you will see the "Find Friends" section, where you can connect to Facebook or sync your phone contacts.

The last section you can choose from is "Invite Friends" for those friends who are not Scrabble players yet."