Write a program to display rate per-hour based on keyboard input recieved

I need a simple program written that will calculate the rate per-hour that it receives a specified keyboard input, then display that result with a simple GUI. The program needs only to do a few simple things. 1. Calculate the rate per-hour rounded to the nearest .01 that the user enters a specific keyboard input. This input will be specified by the end user. This only needs to be a single key, for example the number of times the user hits the + key. 2. Have a way to correct accidental input via another keyboard input, also specified by the end user. For example, if the user accidentally hits the + key for another reason, they should then be able to use the - key to compensate. 3. Display the rate per-hour in a simple format. The display can be as simple as a black background with text over it, but it must be easily readable, the text color must be changeable by the end user, and the size must be adjustable. There must also be a simple title section to display what is being tracked. This program is intended to be used during video game live streams, so examples include "Kills per hour," "Deaths per hour," "XP per hour," etc... 4. The program must have an "always on top," toggle for windows, to avoid losing the display during live streaming sessions. 5. Windows 7 compatibility is a must, Linux and Mac support are not necessary.