Knock Lock is described as 'is simple application that allows you to select area on your display to enable "knock to sleep" feature. Also in app you can select size of area available for knocking'. There are more than 10 alternatives to Knock Lock for a variety of platforms, including Android, Android Tablet, Windows, Linux and BSD. The best alternative is VBLock, which is free. Other great apps like Knock Lock are Next Lock Screen (Free), ClearLock (Free), GO Locker (Free) and Keypad Lock Screen WatchDog (Free Personal).
VBLock is a secure, customization alternative to the built-in Windows lock screen. Its exclusive highlights not found in other programs include securely signing in with two-step authentication, a beautiful Aero Glass background, and a simple, clean interface.
Next Lock Screen is the ultimate lock screen for busy professionals. Next helps protect your phone from unwanted access by others, and you are instantly more productive. It is an excellent productivity locker app and companion for your everyday life.
Keypad Lock Screen WatchDog is application to protect your mobile phone and tablet from third persons with spy camera capture. Screen unlock is impossible without correct password. Access will be granted only when you enter right Passcode.
Not your conventional pin/password/pattern lock. Now you can unlock your device without looking at it! With a combination of swipes in 8 directions (Up, Down, Left, Right, UpRight, UpLeft, DownRight, DownLeft), you can lock your device.