There are some inconsistencies with handling the empty cards.
Currently you allow to create cards with empty Title or Body, but not both. Empty card just silently disappears when you click ‘Finish’ right after card creation. But existing card does not disappears when you delete everything from Title and Body - it just restores the last deleted text when you click ‘Finish’ - which is strange, I’d prefer some warning instead (
Card is empty. Delete? Yes/Cancel).
From another point of view: empty cards may be useful sometimes - as a placeholders for example. Or as a quick editing shortcut: first press ‘New’ button five times. Then add the desired info to the newly created cards…