With Photector you can prevent them from seeing or deleting your photos, allows you to set a password to access the reel and / or deactivate the delete buttons within it.
It does not add an icon, you can configure it from settings.
Requires iOS 4+
You can download it free en Cydia.
You need to have done the jailbreak.
Just the modification I need for when CELEST comes out. To bookmarks I add the page 🙂
THE BEST IS IPROTEC TO ANY APPLICATION PUT A PASSWORD
Perfect!! Now I will have porn photos without having to worry Juas!