I'm new to the mod community and modding and tried to do something with the ui, but can't figure how. I would like to see your source code for this mod, it might help me move onwards.

Ok, all you need to do is download the mod, then look inside the zip file, and all the source code files are there. The UI changes are in the control.lua file, the gui object is created and removed in the toggle_useful_info function, and the information in it is updated in the update_useful_info function. It took me a while to understand how the gui works too :D especially if you want to support different languages as there isn't that much documentation.

I will do that, thank you.