The lock screen is one of the new features introduced with Windows 8. The lock screen is a combination of a cool picture background and notifications. Microsoft has included an option to change the default lock screen background with a custom one.

Computer users who have previously used Windows 7 OS must be knowing about a free tool named Logon Screen Rotator to automatically refresh logon screen background. While Logon Screen Rotator can’t be used to rotate Windows 8 lock screen background picture, a paid app is now available in the Windows 8 Store do the job.

IM Lock Screen Slide Show is a paid app ($1.49) for Windows 8 to automatically refresh the lock screen background picture with a new one every 15 minutes. As the developer notes, IM Lock Screen Slide Show automatically picks up photos from your pictures gallery and displays them as a beautiful slide show on your lock screen.

The current version of IM Lock Screen doesn’t let you choose pictures that you want to see on the lock screen. It blindly picks up pictures from your Pictures library and displays them on the lock screen. So, you need to keep only selected pictures in the Picture library that you want to see on the lock screen.

Another downside of the app is that there is no option available to change the default 15 minutes time interval. Setting up the app is straightforward. Visit the Store, install Lock Screen Slide Show app, run the app, allow the app to run in the background, and finally click or tap Activate IM Slide Show button.

In our test, on Windows 8 x64, the trial version didn’t perform as advertised but it worked fine on another machine running Windows 8 Pro x86. We suggest you test the trial version before buying the app.

Download IM Lock Screen Slide Show (Store link)