I have multiple apps in a package. I don't want to give access to all apps for selected customers. is there a way I can control which app they can access in the package
The platform supports a feature licensing mechanism as described in Manage Features. This allows you to turn on and off features in your managed package via a Feature Management App (FMA) that sits in the same org as your License Management App (LMA).
So you setup a feature for each of your "apps".