On screen overlay center point finder tool.

I need a software engineer who can program a simple application. Basically a bubble in the top left corner of the screen with a button that allows you to select two points on your computer screen and it shows you where the center point between those points is. It will need to allow multiple center points, on screen overlaying the background. Then the menu has a wipe all feature and a close feature.

I am a doctor viewing features in the skull. My existing software doesn’t have a center point feature which I really could use. Im trying to create a program that overrides that problem. If this goes well, there is opportunity to work on future tools of this nature.