You can apply all the updates released to the program as long as you don't change the main version of the product. This means that you can update from 11.0.0.XXXX to 11.1.0.XXXX free of charge but if you want to update from 11.0 to 12.0, you will have to pay a fee. It's usually small because you are already a customer. Yes, you can apply free updates to your application.