Day Slip
A menu bar todo list.
That does only the todo list.
A hotkey opens it from any window.
The plus button adds a task, the checkbox marks it done and strikes it through, double-click edits the text. The next day, yesterday's completed tasks delete themselves. Uncompleted ones carry over and turn red.
That's it. It doesn't do anything else, and it never will — because you don't need it to.
Six settings.
Right-click the icon to open them.