Hey Jeff, I’m probably using the same method you are (https://docs.google.com/spreadsheets/d/{SPREADSHEET ID}/export?gid={SHEET ID}&exportFormat=pdf&format=pdf&portrait=true&single=true&size=0&fitw=false, or some variation of that), which works beautifully on the computer and iOS. But for some quirky reason it doesn’t work on Android, unless the user has a PDF app installed.
If you don’t need it formatted in portrait mode, you can try adding "https://docs.google.com/viewer?url="before the PDF export url. It looks redundant as a link, but this forces it to be opened in the Viewer mode (both on Android and iPhone), which appears in a format similar to PDF. As far as I can tell, there’s no way to add the formatting variables to the Viewer mode…only PDF mode (which again, works on iOS and Computer, but not on Android unless the user had a PDF app installed).
But if you find a way to format it in Viewer mode, I’d love to hear it!
Hope that helps some!