The YouDo task organizer and planner, while not free, can be had for the amount of change you'd find walking a few blocks with a watchful eye on the ground. You could also sing or dance in a public place with a tip jar, and you'd have enough within 5 minutes.
Once obtained, it's time to start organizing. Here are a couple non-standard uses of the software:
Student's day planner
If you're a student, you care about this week. What homework is due, what club meetings do you have to go to, and is there a test this week?
Use YouDo to plan your week. It's easy to scroll through a week and see what's happening.
Workout and exercise log
Use the app to make notes of the days you worked out and what exercises and reps you did at each station. Plan ahead and tap out workouts you're doing later in the week.
Don't waste time picking through categories trying to find the foods you need to buy. Open YouDo, write groceries down as you remember them, and pull the app out while you shop. You don't need a free hand. The only thing you have to do to use it is tap items as you put them into your shopping cart. You literally check things off your list.