When scheduling an email subscription, the option to change between daily and weekly notifications is not avaliable in an app when it is avaliable in a workspace for the same report. I have noticed this only occurs when the report contains connections to multiple databases or servers in SQL Server. It does not happen for muliple data sources, or data models with multiple tables from a sinlge database in SQL Server. Since the desired users cannot be in the workspace, the only workaround is to set the report refresh rate to the rate at which you'd like the emails to be sent. If you would like the report to be refreshed daily, but only receive an email once a week, this cannot be done for these particular reports by scheduling the subscription through the app.