In a scene where Ian and Anthony walk into a arcade, there is an arcade cabinet called 'Sex Simulator'. This was actually used in a deleted scene with a cameo appearance of Shane Dawson, but was removed so the movie could keep its PG-13 rating. But the Arcade Cabinet is still in the movie, just not used.
During the mail man scenes you can see Anthony and Ian live on Gerard Way. Gerard Way is the lead singer of My Chemical Romance.
The film's director, Alex Winter, starred in Bill and Ted's Excellent Adventure (1989) which is also about the traveling adventures of two young California dudes. Both films feature the two leads time jumping to different locations.
The arcade where Ian and Anthony go in the beginning of the movie is called Game Bang. This is a reference to a segment on their Smosh Games channel.
The film finished filming the day before Vidcon in 2014, and almost exactly one year later the film premiered the day before Vidcon (2015).