Iris inquires about how Cisco is so sure that he can bring Barry Allen from the speed force, Cisco tells her that he has been collaborating with Harry, Tina, Tracy, Felicity, and Curtis. He is referring to Harrison Wells (of Earth-2), Mercury Labs' Tina McGee, Tracy Brand (inventor of the speed cannon), and Felicity Smoak and Curtis Holt of Team Arrow.
Cisco uses the phrase "Samurai Jackass," a reference to the Cartoon Network series Samurai Jack (2001).
By mentioning that he spoke to Felicity and Curtis, Cisco reveals that they survived the Lian Yu explosions and are alive, since this episode aired before the season premiere of Arrow, and when previous season ended their lives were at stake.
This episode has a lot of callbacks to the pilot episode, from Barry waking up to "Poker Face" much faster than previously, to the creation of new metas, to many of Barry's ramblings being quotes from the first episode.
While chasing Peek-a-Boo, Cisco declares "I hate teleporters". His comment is amusingly ironic since his breaching powers give him the same ability.