A free app for Android, by Goshiapps.

Door Pattern Lock screen is the best application for users who want to make their phone more secure and creative. If you have a phone with a screen lock, then this app is for you. With this, you will be able to have many different themes on your lock screen. You can change the theme, as well as the background, every day, to make your phone look unique. 

This app is easy to use. All you have to do is choose the theme you like, connect the four dots to make a password, and enter it. You can change the color of the theme to match your phone’s background.