This is awesome, thank you for making it - a much needed program. Other markdown editors I've tried were either too slow, paid, or overly complicated. I was happy to see this in my feed. Its made in good taste, simple and fast.

The only thing that bothers me is the header sizes are a bit small; the smallest header (###### header) is smaller than regular text. I think they need rebalancing to make all headers atleast larger than regular text.