That's it, you can download it and change it the way you like it and use it on your projects.
The functional part of the software it's done and works just like is.gd but if you want to add more functionality you are welcome to.
Because it's free software you are free to change the logos and the design, please read de GPL license in the software.
UPDATE: Five days after this project went online a blog published seven other options to make your own URL Shortener, check it out here: http://rod.gs/Tg