Barry and Iris go to a park near where Joe is being held and Iris admits her feelings in episode 1x15 "Out of Time". Barry talks to the Speed Force in the guise of Iris in episode 2x21 "The Runaway Dinosaur". Barry and H.R. attempt to ambush the collector in the park and Cisco returns later to fight her in a trial by combat in episode 3x11 "Dead or Alive". Appears in 1 more episode.
Olive is leading a cleanup of the bay when it is attacked and later he proposes to Felicity during a press conference in episode 4x09 "Dark Waters". Oliver, Lance, and the new police captain head down to the waterfront to meet an incoming A.R.G.U.S. team coming in underwater in episode 6x12 "All for Nothing".
Izzy meets with Ben to accept his gift and he tells her he has a line on a job in town in episode 3x09 "Asshole, Other Asshole, and the Depressive Muppet". Izzy, Emma, and Jack get looks when they attend a childbirth class together in episode 3x10 "You Be You And I'll Be Me".
Emma joins Jack after talking with her boss and tells him she cares about her family and friends more than her job in episode 3x10 "You Be You And I'll Be Me".