Is there a way to set up a simple poll within Smartsheet? One question, 3 answer options, anonymous. Ideally I would want it to be a pop-up which could be added onto existing sheets.
You could create a Form that has just one question on it (built from a dropdown column in a sheet). Here's a webinar that goes over form creation.
As long as you keep the settings of the form so that users don't have to log into Smartsheet to fill it out, the submissions would be anonymous. (See: Manage Form Display and Submission Options)
This wouldn't be a pop-up over existing sheets, but you could include the live link to the form in the sheet somehow (perhaps the top row, or as a sheet-level comment, or in a Sheet Summary field). You could also embed this form into a dashboard using the Web Content Widget. Would any of these options work for you?