Workflowy's not the best tool for note-taking -- it's great for making structured lists of items that you only need to identify or briefly describe, making it a fantastic e.g. task list, but adding more structure to any particular item is pretty clunky (though at least possible).

I've historically used Keynote NF, but it's PC-only. Currently looking for an app that does the same thing on iDevices, since my iPad's becoming my go-to note-taking tool, but I haven't found anything that does everything I want yet.