the author of this app says:
LookMOBILE is the latest image-viewing client developed by the IDELIX team for Pocket PC and Windows Mobile handheld devices. It enables users to explore JPEG, bitmap, GeoTIFF, or TIFF files using IDELIX's patented PDT lens technology.
Recognizing that it is difficult to interact with rich, detailed information on small screen devices, the IDELIX team is developing new user interfaces to meet this challenge. The PDT lens is an interactive tool in LookMOBILE that improves the user's experience by drawing attention to the most relevant information.
As the resolution of cameras on handheld devices increase and information such as maps become more detailed, the PDT lens in LookMOBILE provides a means of viewing finer detail without zooming most of the image off of the screen.