How can I use this ?  

Well, license here is pretty "super-open", not even copy-left or copy-right, 
basically its close to the WTFPL, just use it as you want, 
as it's the most practical to you : 

* if you want to use it as GIT submodule and compile it in your app, do it ; 
* if you prefer separate project as a shared library, do it ; 
* if you need to modify the project to be able to integrate in you app (opensource or not), do it ; 
* if you want to share you work on the library, thanks a lot, but if you don't, no problem ;
* if you think about some weird case I didn't talk about, well, do whatever you want, I don't need to know about it ;
* if you like it so much you want to spread the word, thank you, you're welcome.

Enjoy !