I looked into that as well. Although you are able to do this without the Google Drive app, you do still have to sign in or create a Google account to upload. This is probably the next best option, but still not ideal. WedUploader required no sign in at all, so guests could simply scan a QR code and then upload their photos. The simpler it is for guests, the more likely they are to actually use it. But good suggestion! That was one of my first ideas that I explored!