How does FitFi work?

So, can you explain to me in simple terms how exactly does FitFi operate? I understand it's some kind of fitness and finance crossover, but I'm curious about the mechanics behind it. How does earning rewards for physical activity actually translate into financial gains? And what sort of platform or technology does FitFi use to track and incentivize this behavior? Is it a mobile app, or something more complex? I'd love to get a clear understanding of how the whole system functions.