My side project is built around a major hack, overriding the pause action on your headphones. Pressing pause will shift from music to podcasts and vice versa. For reference: https://shiftfm.app I made this (with my friend) because we often shift between podcasts and music during workouts, and its just super nice to be able to do it without using your phone.
A couple of years back, I had an idea for an app that would mix podcasts and music nicely into my workouts. There's so much idle time during a workout, so for podcast lovers like me, it's the perfect opportunity to get loads more podcasting time in during the week.
The idea was to listen to podcasts during the relaxing part (think rest between sets, chill during intervals, etc), and have music during the intense parts (lifting, running fast, etc).
In order for it to work without ever having to open the phone, I implementing a workout timer that shifts between podcasts and music. And in addition, being able to shift back and forth through my headphones (tap pause to shift).
I've been iterating (now together with mates) on the concept for two years, and I gotta say this has become a super nice workout experience.
Here's our current problem. We've been featured on the App Store several times, and the acquisition rate has been good. So has retention, really. But the activation rate is the big bottleneck. I think it's because, this is really a new style of workout "entertainment", and kind of hard to explain to people. You really have to try it to realize how great it is (humble/brag opinion). Those users who do get to try it out that first time almost always stick around, but loads of our users don't get there.
I'd really, really love some feedback on the product, and hear some opinions especially on the onboarding, which presumably might be where we struggle. We're building this mostly for our own pleasure, but I really think most people would love this product for their workouts.