QuestTracker

QuestTracker is a straightforward program to keep track of all your tasks in quite a simple way.

Just jot down your tasks to be done (quests) in the left bar and in the right bar add your (optional) short description for each.

As you complete your to-dos, just tick to turn them green so you know you don't have to worry about them anymore.

QuestTracker is a sort of über-simple agenda whose main appeal is just that: its incredible simplicity and fast handling.