I use VSCode as my main IDE. I always felt it lacks a UI element that allows users to navigate through recently opened files as they do in web browsers. I read through the VSCode docs and actually found keyboard shorcuts for doing this. However, I decided to create this extension anyway to reflect their existence in UI too.
I learned VSCode extension API and found a few repos with popular extensions to see how they work with it. Once I got logic working, I took the icons from Microsoft's official repository and configured them to work well with light and dark themes. It allowed me to achieve native user experience. Later I completed it with "return the last edit location" feature which was requested by users.