Very nice work for your very first Pixel Art!
Now for the tools. There are quite a large variety of tools people use for Pixel Art. My personal preference is Pixen, but it only works for Mac. So if you're not on a Mac, then there is quite a large variety. I hear Graphics Gale is good, and I also like Pickle. Its really all about personal preference when it comes to tools!
As cool as this site may be, as a web designer and a person who's dabbled in pixel art for games, it's not really suited for anything serious, unless if you're a pro at using very little tools to make something amazing.
If not, there are many other options that are much more advanced. It's a much better choice to go with a full-fledged pixel art editor like Pixen if you're really trying to create something good. It has support of and patterns, and is quite intuitive, better than a web app equivalent. That is, if you're serious about making pixel art. If not, the online alternatives work just fine.
You should look into Pixen. I have no idea how the two compares, but afaik it is the go-to pixelart program for Mac.
If you like to sprite on the go, Sprite Something for iPad and iPhone is also pretty nice.
I used Pixen for a few things. I liked that it, contrary to some other programs, feels like a native application. It also has some limited animation capabilities.
I am just seeing that it now costs money, but you can check out the git repository and compile it yourself.
I don't know what program he uses, but there's one that I found earlier today that I've been toying with, called Pixen. It's Mac OSX-only, though, so if you're on a Windows PC then I don't really have much to say.