As I've noted in too many other threads to count, I hate the NNG Mazda nav system. I use Waze on my iPhone 6. Waze is pretty awesome. The UI/UX blew me away the first time I used it.
I also listen to a lot of podcasts with Downcast. Until very recently, when Waze would speak a direction the podcast would continue to play behind Waze. This was especially annoying when there was a direction onto a highway with multiple names, resulting in a series of 10-15 second long interruptions of cross-talk from the two apps. This means you need to switch back to Downcast, and rewind the podcast (skip back 15+ seconds), then switch back to Waze (to get Waze back on the screen) to pick up where Waze started yapping.
Something recently changed in either Downcast, Waze, iOS or a combination of those. Downcast will now automatically pause while Waze is speaking, and then resume. It's not perfect in that it doesn't always resume like it is supposed to, but it probably works correctly 85-90% of the time. It's pretty sweet. (If you have the speed hack enabled on the Mazda system, you can just push the play/pause button on the screen to resume.)
I have noticed that music apps like Spotify and Amazon music are not paused, but their volume is automatically reduced while Waze was speaking. That behavior is nothing new, but it is interesting that those behave differently (no pause) than Downcast. I don't need or want the music paused, so that works out great.
I tried the Overcast app a while back, and I used to use the built in Apple podcast app but didn't like either one of those nearly as much as Downcast. They may behave similar to Downcast now, I don't know.
If you listen to podcasts and use your phone for navigation, for this feature alone it's worth checking out Downcast.