Simple, lightweight memo/todo app. Cognitive offloading.
Whenever you add a memo, the first line becomes the title. Subsequent lines can be expanded by clicking the arrow in the view.
The general idea is that you can only have a handful of 'hot' information in your mind at any given time. If it isn't in that small set, then it probably that important so it falls into the 'cold' category. This keeps the total number of things that you're thinking about low, but also makes sure that nothing is ever permanently forgotten.