I have tried almost all of the major podcast apps and have settled on Podcast Addict. Pocketcasts, while having a spectacular interface, insists upon renaming the files to long strings of undecypherable gibberish, such that if you have to factory reset or switch devices, the files you have downloaded, many of which are no longer on their servers, are completely worthless. Having been a phone tester for some time, its insistence on doing this (and I went back and forth with Shifty Jelly's tech support many times on this issue), makes it dead in the water.
Video Podcatcher Deluxe is also an attractive alternative with a good interface, but a sync system that is not quite sufficiently robust.
Podcast Addict has an excellent interface; does not rename files; and provides for complete backup files that can "re-read" the files already on your sdcard and repopulate the app no matter how many times you factory reset or switch devices.
Highly recommended.