2020: Time Travel Movies
https://syncplay.pl/download/ (The Linux .deb seems to require some weird dependencies, but the AppImage works fine.)
Server address: syncplay.pl:8996
Default room: CyberSpace
Enter your name and run.
Uncheck: "Never slow down or rewind others (experimental)".
Check: "Fast-forward if lagging behind."
Check "I'm ready to watch!" (You can also set this to be checked by default in settings.)
Bill & Ted's Excellent Adventure
Back to the Future
The Time Machine (1960)
Austin Powers: The Spy Who Shagged Me
Back to the Future II
The Time Machine (2002)
Back to the Future III