You can set fixed reminders ("Pay credit card bill!") or just add one-time events. You can also turn on reminders so the app pings you either before a task is scheduled, at the time it's scheduled, or as the "absolute deadline" (another field you can fill in) has passed. The reminders are cute and cheeky, too: "When you have a minute: Clean out your inbox," for example. Other useful features are the ability to hide tasks until a certain day and a completion meter that gives a visual representation of how much progress you've made on task-completion.