Who owns Kraken app?

Who exactly is the owner of the Kraken app? I've heard it's a popular platform for trading cryptocurrencies, but I'm not sure who's behind it. Is it a publicly traded company, or is it privately owned? Could you also clarify if there are any notable investors or stakeholders associated with the app? Additionally, I'm curious about the company's history and any notable milestones they've achieved in the cryptocurrency industry.