The Reminder List widget allows you to set and edit reminders at hour or half hour intervals for some hours in the future, perfect for when you say "I should remember to take the pasta out in 10 minutes!". You can also specify a time for a new reminder.
The Time of day widget allows you to set up to 4 times (morning, noon, evening and night) and clicking on any of those buttons will trigger the creation of a reminder for that time of the day, in case the time has pass it will be for tomorrow by default, perfect for when you need to remember to buy something as soon as you get home.
You can add notes to remember what you had to do, if you don't the notification will remind you of the time the reminder was set, hopefully jogging your memory.
On the Reminder List widget, after setting a reminder, pressing on it again will remove it, if you want to change the time or the note, you can toggle edit mode using the pencil icon. Your future reminders will be shown and selecting one will show the edition dialog.