is a Chrome Extension to expose CTA Bus Tracker functionality inside the browser window. This came about because every morning, I would use a bus tracker app to see when the next bus was 3-5 minutes away, and then head out. The extension allows you to select a bus line and stop, and it tracks the next bus coming to the stop for the next 10 minutes, so you can determine the optimal time to leave the house.
It builds the extension icon using minimum-sized fonts and some fun layering - that could be some nice reference material.