Isolating pocket casts from scrobble for last.fm
Last.fm picks up the intents apps like Pocket Casts and Google Music send to bluetooth devices, and hacks that into their scrobble implementation. I guess they figured Google were never going to support them explicitly so that was their only way in. To stop Pocket Casts from scrobbling you'd un-tick the Google Music option in last.fm.

The fine people of Pocket Casts (read: us) are planning to put in a setting that turns off that bluetooth data, which would also turn off scrobbling. We looked into the last.fm API and there's nothing extra we can send to tell them to ignore us, which would be a better solution, since it would mean keeping the blue tooth meta data as well.