Alexis Wajsbrot and Damien Macé mentioned they made Don't Hang Up (2016) as an homage to the teen slasher movies from the 90s including Wes Craven's Scream - Schrei! (1996) and Jim Gillespie's Ich weiß, was du letzten Sommer getan hast (1997).
The movie played on T.V. is Red Balloon the first short film directed by Alexis Wajsbrot and Damien Mace.
When Brady makes the phone call to the neighbor Larry he uses the alias "Brad Gunderson" and portrays a North Dakotan accent. This is an homage to Fargo (1996). One of the main characters is Marge Gunderson played by Frances McMormand.
They used two actors to play Mr. Lee, they also did the same for the Stranger in the film When a Stranger Calls (2006)