try plugging your phone into itunes and clicking on the App tab, when it brings up the list of apps have a look down and see if the camera is in there, if not then try restoring your from a back from before you lost your cam, so say you lost cam app two days ago restore your phone from a back up from 4 days ago.
hope this helps - the steps below will give you steps how to restore your iphone, but make sure you restore from a back up!!
Use the following steps to restore your device:
- Make sure you have the latest version of iTunes installed and running before attempting to update.
- Connect your device to your computer.
- Select your iPhone, iPad, or iPod touch when it appears in iTunes under Devices.
- Select the Summary tab.
- Select the Restore option.
prompted to back up your settings before restoring, select the Back Up
option (as seen in the image below). If you have just backed up the
device, it is not necessary to create another.
the Restore option when iTunes prompts you (as long as you've backed up
your device, you should not have to worry about restoring your phone).
- Once the restore process has completed, the device restarts and displays the Apple logo while starting up:
For the iPhone only, after a restore, the iPhone displays the "Connect
to iTunes" screen. Keep your device connected until the "Connect to
iTunes" screen goes away or you see "iPhone is activated." If iTunes
does not have an Internet connection, you cannot complete this step.
final step is to restore your device from a previous backup. Once your
device is restored and-in the case of the iPhone-in the process of
activating, you should be able to see the following in iTunes:
Select the backup you want for your device and select the Continue button to complete your device's restoration.
you do not want to restore from backup, select "Set up as new..." If you
want to preserve previous backups that iTunes has made, be sure to back
up the appropriate directory before choosing to set up as new. To learn
more about setting up your device as new, see How to set up your iPhone, iPad, or iPod touch as a new device