Sonarr
Smart PVR for newsgroup and bittorrent users
...It monitors RSS feeds for new episodes of TV shows, automatically downloads, sorts, and renames them, and can upgrade existing downloads when a better quality version becomes available. Support for major platforms: Windows, Linux, macOS, Raspberry Pi, etc. Automatically detects new episodes. Can scan your existing library and download any missing episodes. Can watch for better quality of the episodes you already have and do an automatic upgrade. eg. from DVD to Blu-Ray.