Like many people, I use WorkFlowy for my To-Do list. I employ a strategy similar to GTD (Getting Things Done) where I add tasks to my Inbox and then sort them later into appropriate categories.
We recently updated WorkFlowy so that you can drag an item directly under a collapsed list. When you do so the item will get added to the top without the list being expanded (accompanied by a cute animation).
As the video below illustrates, this allows one to quickly sort through an inbox by dragging items into the desired lists without them opening up and getting in your way.
Give it a try!