Locktopus is an iOS modification for jailbroken devices that allows you to password-protect individual applications directly from the home screen. Locktopus will prevent locked applications from being launched unless the correct password is provided.
Locktopus works on all devices with modern, jailbroken firmwares (3.x-4.x).
There is no homescreen icon or standalone application; Locktopus just becomes part of iOS. When the home screen is in edit mode (when the icons are wiggling), Locktopus gives each icon a button used to lock or unlock the application.
$2
Locktopus is available in the Cydia Store from the BigBoss repository.
Locktopus 2 is a free update for current customers. The tweak has been completely rewritten and adds the following new features:
Very soon.