if I choose a Public Plan can I know the username or the user email?
You can build e-mail capture into your app flow even if your user does not need to authenticate up front to log into the app.
But there are some limitations; you will not have a variable like USEREMAIL() available to use in your expressions.
I have been working on approaches for apps that initially don’t require sign-in or authentication for a user to browse, but later require at least an e-mail address to perform certain functions.
I would love to hear how others are approaching this.