Restrict User Access

[Inquisitive]

Hello,

I am creating an app. The users will use the app to add new records to a spreadsheet, and they will be able to update their existing records.

The users must not be able to see other people’s data. Is there a way to restrict their access so they can only see the data in one spreadsheet in the workbook? Or will I need to create a different app for every different user. I imagine that could become very expensive