The AHA moment of GpxOverlay

I was on my Portugal-Poland Europe backpacking trip. The trip was supposed to be the last 2 months of my travelling 9 months. After that, I need to go back to work (full-time, because all my business ideas failed).
I knew I wanted to share some videos from there. I liked riding downhill, but the camera often showed how fast or steep it was. So overlays with the speed would be amazing. The only 2 tools I was familiar with were either ridiculously clunky or expensive. Then I connected the dots - I can make it on my own. It can't be too difficult. It is just a timestamp and coordinates. I made the prototype I used in my video in one day.