You would need to create a single table for your users info like name,mail,password, etc.
Then create a new table to assign an id to each app you want to manage.
Finally you'll need a permissions table with an id_user column and an id_app column to bind the app to your user.
In each app you'll need to specify its "id" based on the apps table you created before. When a user logs in simply store in an SESSION array all the id_app values from the permissions table where the user's id appears and use in_array function to verify if the user is allowed to access the app.