If you have a bit.ly account, you can get a public API token which can be used to create shortcodes. This is really handy in my situation, where I'm creating a ton of feedback spreadsheets (another monster post on that later). Using a small code snippet, you can create a feedback form, throw in some code, and have it display as a short URL and QR code.
If you're starting from scratch, create a template form and spreadsheet. When you need to make a feedback form, use File > Make a copy on the spreadsheet to copy over the code.
Otherwise, you can make a copy of this blank template to get started (code is already inserted). If you're going to make your own, be sure you have a form linked. If there is no form on your sheet, you'll get an error.
The full source code is below. Note that there are two files: one called Code.gs and one called popup.html. If you're copying/pasting, you need to create an HTML file (File > New > Html file in the script editor) and call it 'popup'.
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The wheels of the web keep spinning...