Sonarr is a PVR (Personal Video Recorder) for BitTorrent and Usenet users. It can monitor multiple RSS feeds for new TV show episodes, download and rename them. It can also be configured to automatically upgrade the quality of files already downloaded when a better quality format becomes available.
Sonarr supports specials and multi-episode releases and is backed with a automatic failed download handling. It is available for Windows, Linux, OSX and Raspberry Pi.