iOS 7 't need to be up to date on all of your applications before downloading available.
also recommend that you back up the data before updating your device.
iPhone backup To take Settings> iCloud > Storage & Backup section reached the"Backup Now"(Back Up Now) button, press the
g backup your device before starting the erection photos, applications, etc.. it contains delete is recommended. This will speed up the backup process.
for backup through iTunes is installed on your computer and iPhone with iTunes while the iPhone is connected to a computer via a USB cable, select and Spare Al (Back Up to Now) need to click the button.
the size of the new operating system will be a rather large updates over Wi-Fi instead of 3G recommend that you do.
Update before you choose a Mac downloaded to the computer, then install a transfer cable to your device through the operating system possible.