Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

hydrus for a desktop application for managing a personal collection of images, videos, and other files.

Spotiflyer downloads playlists from Spotify and many other services.

(didn't see you posted this one as I was posting it)

yt-dlp youtube-dl fork that is more current and works better for tons of sites to download media.

Deluge run headless. Great Android mobile app.

Tautulli for monitoring and tracking your Plex Media Server usage and performance.

Ombi for a self-hosted web application that allows users to request content for Plex, Emby, or Jellyfin.

eiskaltdcpp for a cross-platform program that uses the Direct Connect and ADC protocols.

beets music library management and tagging for geeks

TMSU for a command-line tool for tagging your files and accessing them through a virtual filesystem.

digikam for image and video collection management and viewing (also does duplicate detection)

Fopnu for a P2P file-sharing system with no ads, no spyware, and no bundled software.

FrostWire for a BitTorrent client and media player with built-in search functionality.

DupeGuru for finding duplicate files on your computer.

Plex for Movies / Shows / Music.

SuperTag for a command-line tool to manage files using tags instead of folders.

Mylar3 for an automated Comic Book (cbr/cbz) downloader program for use with NZB and torrents.

mediarepo for a media manager similar to image boards (boorus), allows tagging media and searching using those tags.

Stash for organizing and serving adult video and image files.

Media Center Master the free version is a cool utility for organizing movies/TV shows that will find and attach metadata. The premium license unlocks torrent/Usenet integration and will automatically find download new episodes or movies as they come out based on your preferences

LaunchBox for a game launcher and organizer for Windows.

LazyLibrarian for following authors and grabbing metadata for digital reading needs.