Sorry if this type of thing isn't allowed, I don't see a third party applicaiton board.
I have been using NZBget for a long while and think its great
However, as I use it on very low powered hardware I have never been able to use the likes of Sickbeard or Episode Butler. So, I have written a small, Perl script that does (almost) everything Sickbeard does. The script is a command line, menu driven application. You can search for shows and add them. The script then connects to the internet and collects show/episode info. You then further configure it for the shows you have seen, set it to run on a schedule and it will keep your shows up to date, sending the NZBs to NZBGet - almost exactly like Sickbeard does.
Don't get me wrong, if you're hardware can manage it, Sickbeard is a better app. My problem is that my box (Raspberry Pi etc) doesn't run it too smoothly.
Anyway, I have it up here -> https://github.com/showdypi/Showdy-PI
and would really appreiciate any feedback etc.