There is a website out there that litterally allows you to create invisible apps on your homescreen by only adding links to your homescreen with a built in iOS feature! So obviously no jailbreak :>
So your probably wondering how do you do this magic? All you have to do is go to iempty.tooliphone.net on your iOS device, Take a picture of your homescreen in "Wiggle Mode" (Hold an app) Then choose which icon you'd like to turn invisible, then add the web page it redirects you too, to your homescreen, drag it into place and BAM you have an invisible app! Here are some example:
Pretty neat!