Chrome Webstore, in the QnA session, it is said that these apps are essentially just web apps that all browsers can view them right? How does paid app works? I

Chrome Webstore, in the QnA session, it is said that these apps are essentially just web apps that all browsers can view them right? How does paid app works? If i paid for a webapp/game on the webstore... and some day i have no access to Chrome, am i still able to open that webapp on any browser at all?