Yeah, unless you jailbreak there is no way to hide apps on a stock iPhone unless you hide them in a folder. Now if you jailbreak you are must know what are the tweaks/apps you've installed on your phone to hide apps, go to settings> general/ scroll down and you will see most of your installed jailbreak apps lists there, you can also install "apps info" application from cydia and it will give you the list and the use of all tweaks/apps you have installed on your phone.