For that you need an app like iExplorer which lets you view all the files on your iPhone or iPad (or, iPod touch).
How is that possible? Plug your iDevice into your Mac or PC (a version runs on Windows, too). Then, open iExplorer and from your Mac you can view all the files and folders on your iPhone or iPad, and even copy files and folders back and forth.
Music Transfer: iTunes syncs media to your iDevice, but iExplorer gives you manual options to avoid duplicates, search for specific songs, even recover playlists which have gotten lost in the transfer (it happens).
Auto Transfer: iExplorer is a good way to use your iPhone or iPad or iPod touch as a backup for your Mac’s music files. The Auto Transfer button also knows which tracks are missing from iTunes and it puts everything back where it should.
Finder! Finder!: iExplorer mounts your iDevice right on the Mac’s Desktop like a flash or thumb drive. Use the app to view the file system just like you’d view photos on a digital camera’s flash card.
Save Stuff: Your iPhone has information you can also view from your Mac. Save voice mail messages, browse, backup, export, and copy data from Address Book and Contacts, iCal and Calendar, Reminders, notes and other apps.
Messages: Why keep your entire history of messages on your iPhone? iExplorer lets you back them up to your Mac, including iMessage and standard SMS text messages using the Finder-like interface.
Photos & Videos: Those little iDevices are tricky beasts and store all kinds of photos and videos in file formats and databases. iExplorer makes it easy to find and view each one, and plays videos right in the app.
iExplorer is visually slick and sassy and can do all that viewing, copying, and backing up without the need to jailbreak (and potentially brick) your iPhone or iPad.
The only negative is the price tag.
We live in the era of inexpensive apps, thanks to the Mac App Store and iTunes App Store. So it’s something of a shock when a useful app that was once free goes commercial. And not just a little bit commercial, either.