CoinOS is the name of both an open source POS web app and the company behind most of its development, an offshoot of the Bitcoin Co-op from Vancouver, Canada. It was conceived to help spread Bitcoin adoption in the physical business world, and is widely used by Canadian cryptocurrency-accepting businesses, whom we promote using events and social media. We've always had a completely no-fee structure--fiat conversion has traditionally been handled manually, but will soon be automated as we upgrade our website. We maintain a server running the software, and you can make your own free POS page there at www.coinos.io