Which app can I sell my Pi?

I'm curious to know, which specific application can I utilize to sell my Pi cryptocurrency? I've been mining Pi for some time now and am looking for a reliable platform to cash out my earnings. Is there a particular app that's popular among the Pi community for selling their coins? Additionally, what are the fees associated with selling Pi through this app, and how secure is the transaction process? It would be great to have a clear understanding of the best options available before making a decision.