I've tried so far StackEdit, Dillinger and Markable.in, but they all fail when it comes to autoscroll the preview properly when your Markdown includes tall images:
- Markable.in: always scrolls the preview to the bottom
- Dillinger: doesn't autoscroll at all
- StackEdit: scroll doesn't take into account image height
- Hashify: doesn't auto-scroll at all
