Paste text to card and then split this text to several cards (by paragraph or by list item (if I paste lists)). I don’t like to split it manually each time.
Split by list level:
Split on the same level by paragraph:
Possibility to upload files and images (not only insert links to external files)
Import from markdown based on header level. H1 goes to level1, H2 to level2, …
Code syntax highlighting (based, for example on highlightjs)
def hello(): print("Hello world")
Latex formulas (based on MathJax)
Tree changelog. I don’t know how you can implement it, but I need to see what was changed after my last visit.
Undo changes (restore from history). Export markdown to github (if it will be possible to import it back as I mentioned in “Important” section)
Move cards (and linked cards) to another tree
Emoji like on github =)
For tree sharing I think you need to have some namespace in the url, for example, gingkoapp.com/username/treename