This is basically a simple, self-centered pixel art application designed to meet my own desires when making simple spritesheets. It's designed to be straightforward and efficient whilst supporting live animation previews and quick workflow. It's not particularly feature heavy and it's certainly not meant for others to use but I'm happy to share the most recent (least broken) version in case anyone wants a peek.
Click To Try It Out Chrome: supported
IE: supported (but I don't trust it)