Code. This app uses the BackgroundSubtractorMOG algorithm from OpenCV's android library to identify objects in motion from the camera and draws a red overlay around/over them. The ideal is to have nice contours drawn around the objects that are moving. A slider is also added for the user to adjust the learning rate, which may or may not have any effect on the contours.
Get the .apk installer of OpenCV Movement Detect 1.0 that is provided for free and read users' reviews on Droid Informer. The file size is 364 KB and the app is developed for Android 2.2 and higher. The antivirus report shows that this application is safe. Winterhanda is the creator of the tool that belongs to the Libraries & Demo category.
Google Play shows that OpenCV Movement Detect is rated 3.6 by its users. The app is very popular among Samsung and Lenovo users.