AttachSave 4.0 (all versions) now adds Google Drive support (thanks to John Martens for the inspiration and testing). While Google Drive lets you save your file locally, it keeps it in a private area of the SD card so that you cannot normally access it except via the Google Drive app. If you use the Send file option in Google Drive, you can now use AttachSave to copy that file out of the private app area and into your public storage area somewhere.
Enjoy!