I believe you are right. Unfortunately, it seems that TPB is dead and not coming back. We would need somebody to re-write this app to get it going again. It seems that the developers have given up with this app. I was hoping for TVshows 3 myslef though, but what can you do.
If you are interested in still using this app, make custom feeds of your subscriptions, if the feeds work, so should the app.
I tried showRSS feeds, but unfortunately most of the showRSS feeds are useless. so that did not work.
But with proper custom feeds the app does work.