Hmm. Tunein used to be relatively OK with battery use, but they had a pretty big version change about a month ago with even more intrusive ads that I mistakenly updated to. ooTunes is not a bad alternative - I might go back to that.
Yeah, I had everything off, Airplane Mode, screen off. Listened to a podcast for 1hr 15m and it used 35% of the battery and the phone was warm. Using no audio and the battery and temp is fine.Use any audio, bam.
My podcasts app runs just great, not a battery drain at all. But I too do have battery issues with TuneIn, a lot worse than it used to be. Might be iOS 8 + TuneIn, can't really isolate it to Tune In, could just be the way it interacts with the beta.
I'm glad im not the only one! AT First I thought it was beta 4 in general, but specifically it seems to beats or 3rd party audio apps. The music apple app works fine. Beats however, burns my battery literally lol. However, if it's charging it doesn't loose battery just charges really slow.