Very cool idea, and impressive you had this done in a week! I also found the page turning a little confusing, once I realised where the sweet spot is it was fine though. I was confused at first about how the files worked - the first few files I thought I lost, or I was unsure how to get rid of the letter on screen. It would have been fun if you can drag and drop the files into the boxes for some more interaction.
Overall very impressive work!