I have a workflow rather than one tool. I start the day by free writing 750 words of "morning pages" (google Julia Cameron if you want to know more) on ilys. It sounds strange but the inability to see your writing as you type, and not being allowed to backspace means that you are more likely to write honestly and with energy. I really recommend trying it before dismissing such an eccentric approach.
You can then edit what you've written on the site itself--which is private. I then copy and past my entries into DayOne which is by far the best journaling app I have found.
