Back in 2023, my favorite app while learning how to run was WeavRun, an IOS app that changed the pace of the music playing when you sped up. One issue I had is that when I'd go running I'd often fall below the pace I wanted to go at but didn't get real-time feedback or motivation during the moment. I
emailed the company with the feature idea, got a meeting with the Head of Product 4 days later, and came to that meeting with a full working prototype having learned Swift over the weekend. I got design feedback and an offer to be added as a developer to WeavRun so I could use it after they shut it down! I also had a buzzing mode instead of noise for folks with limited hearing. 2 years later Apple launched Workout Buddy - validating the pain point.