Overcast and Huffduffer
It plays nicely with Huffduffer. If you want to listen to any Huffduffer feed in Overcast, it’s a straightforward process.
It’s pretty straightforward to subscribe to Huffduffer URLs in other iOS apps too. Matt has written up the process of using Huffduffer and Instacast. And there’s also a write-up of using Huffduffer and Downcast.