This free online tool uses your webcam to monitor any activity based on motion detection. You can adjust sensor or use default configuration. Any movement create a snapshot.
How secure is this?
Once the page has been loaded in your browser, no communication occurs with the server. All your pictures are kept confidential inside your browser. Even if you lose internet conection, the application will still work.
Sensitivity: your camera can generate noise on the picture. "fine" is sensitive to noise. "low" is less sensitive. Threshold: "Fine" for a snapshot on very small movement such as eye blinking. "high" requires a much bigger movement.
Only HTML5 compatible browsers (Chrome, latest version of Firefox...) can use this application. A webcam is required and has to be authorized each time you start this tool.