TVShows only downloads rars and folders!
TVShows uses The Pirate Bay to find the fastest available torrents. This means that they may be not released just with a video file, but maybe with rars or folders inside.
Some of them could be avoided if the app waited a few hours for the best version to be released, but most of the rar files come from HD releases that are not available in any other format.
If you deselect the Use additional sources for HD (may contain rars) option, the app will wait 12 hours for the good torrents (.avi and .mkv) to appear. If 12 hours after the episode is aired the good sources did not release it, then the additional sources will be used. Advanced users can tweak this behaviour.