Any way to access my private spreadsheet and user email at the same time?

[Terry Gamel]

I'm using google visualization in a google web app to display some information from a spreadsheet.

That spreadsheet includes some public information that is only ever read, not written, by the app.

However, my app is only useful if users can store some of their own information.  My hope was to do that by picking up their email address (perhaps using getActiveUser()) and opening a new tab in the spreadsheet with their email address as the title - or, perhaps, in another spreadsheet entirely, one that requires some kind of authorization to access unless you're doing so through the app.

Unfortunately, it seems like locking down a spreadsheet like that requires me to deploy the web app to run as me, which gets rid of my ability to capture the email address...

Anyone know a way to accomplish this?  Difficulty: I'm not using gsuites or any kind of pro cloud package... just free user....