3delite Screen Item Detector - is a helpful utility that can scan your desktop at regular intervals and detect the presence of a picture that has been selected beforehand.
It can provide multiple types of notifications and offers several customization options, but it features an outdated UI and lacks documentation.
It is often necessary to monitor content that is displayed on your screen, whether you wish to keep track of other users’ activities or log your own usage habits.
Features
• Scan and detect an image that appears on the desktop screen
• Detect if a screen region changes (detect screen change)
• Multiple search items are supported
• Multi-monitor setups supported
• Specify screen region to monitor
• Search images with alpha channel are fully supported
• Pop-up a dialog, play a notification sound, send an e-mail and/or run an application/script when the picture is detected
Download: 
3delite.Screen.Item.Detector.1.0.40.48.rar - 35.7 MB