There is Sailfish OS, been using it for a couple of years now... works pretty great. Not free, but that's kind of the point, you pay for a product so they don't have to get your money in some hidden way.
There are native apps, and you can download Android apps from open app stores. I was surprised how many companies deploy to these open stores, like my own bank.
"Sailfish OS is a European alternative to dominating mobile operating systems"