how to get formfilter to work?

This is a tricky module because the submit button that appears looks like it is part of the actual form you are filtering. It isn't, however. After you check the appropriate checkboxes, hit submit. It should work, BUT the even trickier thing is that the form you now see won't be filter!!!? That is because you are probably logged in as the main admin and by default the #1 admin has permissions to view the unfiltered forms. If you create another role that has access to the form you filtered, but don't give that role permission to access unfiltered forms, then it will work.

Thanks ruralrooster for the clear explanation. If anyone has suggestions for how to make this more intuitive or at least improve cues, that would be great.

Maybe you could add a button where it says "submit" and "preview.." that says "view filtered form" or conversely "view unfiltered form" and have it save the selected option for future visits to the form. Also you could make a box around the filter submit, etc. buttons that labels it as part of the filter script so that it doesn't look like the form's submit button.

This module would be more beneficial if it worked for the admin; "Form Filtering" in lieu of "Filter This Form." This would allow the admin to change the filtered elements.

I suggest that when logged in as someone who can see the forms, they could be made visually different if they would otherwise be filtered—could they be rendered in grey rather than black borders and text, for instance, and done so reliably across platforms?

I added a message in formfilter ui module letting admins know they need to submit the form to save the filters. This may help.