Gaps searches through your Plex Server or local folders for all movies, then queries for known movies in the same collection. If those movies don't exist in your library, Gaps will recommend getting those movies, legally of course.
Gaps is a FOSS application. An example of Gaps running would be having a copy of 'Alien (1979)' and Gaps recommending 'Aliens (1986)' and 'Alien³ (1992)' to be added to your collection.
TIP ME !!
Your gratitude and finance will help me to continue integration of this QPKG and maintain up to date versions.