Does itunes really backup everything?

I have a iphone4s with 7.0.6 but i want to restore it. I have a called photo vault. I have saved there almost 400 pics and i don't want to lose them and btw, they are private photos, thats why it is in the app. Will Itunes if backup my iphone correctly restore really everything when i back it up. Like everything! The pics in the app or my game save or my whatsapp chat history and photos.
please help me, i really need to know this fast before my father gets my iphone. Please
i hope some helps me.

Added (1). Please

It will restore the apps but I don't know about the apps internally.

ITunes performes a backup copy of everything you mentioned above except for the Whatsapp chat history, because, although it has information about every application you had so you can redownload them again, it does not have the information that were inside the apps themselves. So, if you recently linked your iPhone with your iTunes account, it should contain every information you had, so you can performe a safe backup.
You can check if you have the "backup" folder in your computer through the following link:
http://support.apple.com/.../kb/ht4946
Now there should be no problem, but just in case the Apple method does not work, you can download the program Syncios for your computer and copy everything you want from your iPhone to your computer, do your iPhone restore, and then upload every information back to your iPhone (I do not believe that this program also has the in-app informations).

Hope it helped, good luck!