What's here is good, but not enough.
I was hoping for something that let us make more than one style of signature.
The one you've got is kinda nice looking and certainly fits in with the NG look, but it also looks kinda generic, with all the NG icons and plain text alongside the bg we see everywhere.
You need to change it so when we enter a message, it keeps it. And correct the grammar. "your", not "you're".
And frankly, though I assume you've done a bit of work in editing the bg and icons, anyone with gimp/paint could surely add on text with hundreds of font styles, without having to deal with these issues.
If it had a wider range of possible outcomes - like maybe 10 backgrounds, 10 pictures to drag around and a text box that we can move and doesn't have these issues, then it might be actually good.
As is, it just feels far too limiting.
I really liked the colours on the forward/back buttons though - perfect mimicry.