seperate database for each user logged in

[gaurav74]

How can I create an app where each new user who logs in to the app (after I share my app with them) has their own/separate Google sheet for storing data? and each user's google sheet will be stored in their google drive only. idea is to prevent other users of the app or creator of the app to view/edit/delete data for each logged in user. it could be google sheet or appsheet database or any other data repository on cloud. 

Also important to know and understand is how does the billing work in this scenario. Please guide/advise.

[AleksiAlkio]

You are looking for a functionality called "Private tables". Check the article from help pages and its pros and cons. Using this feature, the subscription goes with the same way.. all app users need a license when the app is deployed.