On the whole, it would not be an enjoyable experience to read documents on cellular phones or electronic readers with their tiny size of the screen. Namely, to view the entire content, the user may need to keep scrolling up and down and resizing the content manually. Thanks to the advances of gaze tracker development, which have made potential to integrate the function of gaze tracking and automatic image magnification function on the reader to improve the user experiences. In this paper, we present a new tool that detects the user gaze point on the screen and resize the local image to improve the visibility. The tool integrates a visible-spectrum gaze tracker, fixation/saccade analyzer, and image magnifier. In order to further upgrade the user experience, a new motion scheme of the viewing window has been proposed and the system meets the real-time requirement for the application.