USB Disk Pro (on sale for US$0.99 this weekend) lets you store, manage and view documents and move them between your Mac and your iOS device. The app has an extensive feature set, and you can get complete details at the App Store.
I'll hit some of the highlights:
- View and download email attachments
- Easily transfer files via USB or a WiFi network
- Support for Dropbox, Google Drive, SkyDrive, Evernote
- Support for reading PDF files, MS Office docs, iWork docs, most image formats, many audio and video formats
- Multiple document viewing
I gave the app a try, hooking my iPad to my Mac with a USB cable. I opened iTunes and selected USB Disk Pro as the sharing app. I then could access any file on my Mac, and easily transfer it to USB Disk Pro. I tried some moving some photos from my Mac to the iPad, and they instantly showed up on my iPad screen (running USB Disk Pro, of course). I then saved the photos to my camera roll. Documents, audio files and other file types are also easily moved.
This latest version of the app supports annotation of PDF files, works with AirPrint, and it's iOS 7 ready.