This would enable showing users how they are going relative to the whole user community, which is a common usage scenario.
For example, the chart below has red bars showing the range (min to max) for all users, and blue dots showing the logged-in user's individual data...
I managed to create the above with an Aggregate Formula in a Pivot Chart, but I had to hard-code the user ID to a specific value, not have it dynamically update to whichever user is logged in.
This is currently impossible in Zoho Creator. While there is the Deluge system variable zoho.loginuser, Aggregate Formulas don't allow Deluge variables. It seems this is because Pivot Charts and Aggregate Formula are actually from Zoho Analytics, and have been kind of hacked into Zoho Creator with (uncharactersitcally for Zoho) poor integration.
I'm currently evaluating Zoho Creator for an app we are looking to build, and the lack of this ability means we'll probably have to go with another solultion, which is a shame, because Creator has satisfied all of our other criteria.