You can create polls on files with PollUnit. Students can then check each uploaded file in a tabular view. If you provide PDFs, your students can read the pages online right away. You can also add pages later. Users with an (optional) account will receive an email that a new file has been added.
I attach an example of a logo vote. In your case you would see a PDF download icon instead of the logos and checkboxes instead of the starrating. Also, the background image might not be the most suitable for the students (or maybe it is) - you can choose from a variety of backgrounds.
Start by clicking "Create PollUnit" > "Voting" > "Image / File"
You can create polls with up to 40 participants for free. If you have more students you need an payed account. All updates are in realtime (without page reload).
More infos can be found here: https://pollunit.com/en/voting
Disclosure: I am one of the developers.