I have some functionality that only works in Survey123. I would like to display a label if the web form is being used and hide the label if the app is being used. Is this possible with pulldata()?
There isn't a "switch" you can look at.
But, you can use the deviceid parameter (see below) as a stand-in.
deviceid won't appear for web forms, so if(${device_id}='deviceid not found',1,0) should work for that purpose.