In order to access the root folder of iOS, you would need to Jailbreak your device and install afc2add from Cydia.
Without Jailbreak, you’ll still have read/write access to the Media and Apps directories in iExplorer as well as read access to some of the most commonly used files such as music, photos, videos, text messages, and a lot more. You’ll also be able to access a lot of data close to the root in the Backups Explorer section under Backups.
An iOS 7 Jailbreak was released recently called evasi0n which you can find out more about here: http://evasi0n.com. Once you Jailbreak your device and install afc2add from the Cydia app store, you’ll then be able to access the root (/) folder of iOS.