You might want to ignore reecenitro, if you can even read what he wrote.
First off, this is easily the most frequently asked question on the forum. The usual response is to search and to read what Badspot has posted in the FAQ.
Q: How do I make my own add-ons?
A: If you can't figure this out on your own you will never be able to do it.
However, since I'm not strained to within an inch of my life with answering this question multiple times a day like is often the case, I will tell you what you need to do:
1. Make a model using a modeling program. Blender and Milkshape are two of the most common ones.
2. Create a script for your add-on. Learning to script can be difficult. Look into some of the add-on scripts in you add-ons folder and alter them to see what things do. After you get a feel for what different lines of code do, you'll be able to begin making your own scripts.
If you cannot figure out what to do from here, making add-ons is not for you.