CThruView Transparent Image Viewer - CThruView is a free transparent image viewer that allows mouse clicks to go through the image.
Cleanmock - Create stunning mockups that make your design standout.
LayerX - An intuitive app to display transparent images on screen.
Mock - Instantly create video mockups from screen recordings
Osiva - Osiva" is an acronym that stands for "Overly Simple Image Viewing
Mokup Frames - Create amazing Dribbble-ready GIFs or videos in a few clicks