For Android: It depends on your needs. For better user experience I'd say PocketCasts. For best customization Podcast Republic, Podcast Addict. AntennaPod was for a while the only open source project, PocketCasts is now open source too. If that matters to you, go with those. I like AntennaPod, specifically the sleep timer. However it has some downsides: discovery / search sucks and it's hard to access the queue quickly if your phone uses gesture navigation.

For iOS: pocket casts, overcast

I use it too...but I like to spell it KeepAss.

I can't stand ads or subscriptions. However sync has a one time purchase ad removal. To me it was worth it to support the development and make my lemmy experience more enjoyable.

And just like that, all the other lemmy clients mean nothing to me. Just the handling of media posts is next level compared to the other guys.

Or subscribe to both and get double dosage of fun.

I'm really sorry you are going through that. Best of luck round-house-kicking cancer in the butthole!