Reminders, of course, is a tool for recording and storing todo lists, tasks, and any other little bits you want to remember. If you're familiar with the Reminders iOS app, you'll feel right at home in the Mountain Lion version, which is a near-perfect clone.
As with the iPad version of Reminders, the application presents a list of all your lists on the left, with a faux sheet of wide-ruled looseleaf paper on the right.
Because Reminders can sync via iCloud, your Mac and your iOS device can share one common set of todos. They do so via accounts: In lieu of a Preferences option under the Reminders menu, you'll find an entry entitled Accounts. Selecting that actually opens the Mail, Contacts & Calendars pane of System Preferences. There, you can add any iCloud accounts you'd like to use for syncing Reminders. Reminders also works with CalDAV services including Google Calendar and Yahoo Calendar; you can similarly add those accounts in System Preferences.
Making a list
To create a new list, you choose File -> New List, double-click on a blank section within the lists sidebar, or click on the Plus (+) icon at the lower left of the Reminders window. The other buttons down there toggle the list sidebar and a small calendar that indicates the dates for which you have reminders scheduled.
To delete a list, Control- or right-click on it and choose Delete. You can also use that contextual menu to open a list in its own window, or rename it.
You click on lists to navigate between them. If you use a multitouch input device, you can also use two-fingers wipes left and right to navigate across your lists.
When you're ready to start adding tasks, you again have multiple input options: You can choose File -> New Reminder, click on the next blank line on your list, double-click anywhere below the last task on your list, or click on the Plus (+) icon at the upper right of the Reminders window. As you type in a new task, or after you hover over any task with the mouse for a moment, an i icon appears on the right; click it to configure extra details for your reminder. You can instead double-click a task to accomplish the same thing.
When and where
Among the extras you can set are options for when Reminders should remind you: You can choose to be reminded at a specific date and time, or when you arrive at or leave from a specific location. Reminders in iOS 5 limited location-based reminders to addresses linked to your contacts, though Apple says that's improved in iOS 6. Mountain Lion already allows you to set those reminders to any address of your choosing.
If you check the At a Location checkbox, you're then prompted to provide details about the location you'd like to use. You can either enter a contact's name (provided that contact has an associated address in Contacts) or street address. Then you choose whether you wish to be reminded when you arrive it or depart from that location.
Any scheduled reminders will appear in Notification Center on your Mac; you can snooze them or close them when they pop up. Snoozing resounds your reminder fifteen minutes later--not just on your Mac, but on any iCloud-synced iOS devices.
Other per-reminder options include recurrence, priority level, and the ability to add a note. Adjusting priorities doesn't change where tasks appear in your list, but it does add an exclamation-point icon to indicate which tasks are more important. You can drag and drop to rearrange tasks, or even drag tasks between lists.
Keyboard navigation fiends, take note: You can type the first couple letters of a task to select it; then Command-I to edit it.
To mark a task a complete, click on its checkbox (or, with the task selected, hit the Space bar). You can view all your completed tasks, across all your lists, by choosing the Completed list in the sidebar. To see per-list completed tasks, scroll up past the first item in the list to reveal its own Completed section.
Though iCloud offers support for shared Reminder lists, you can't create such lists in the desktop app--instead, you'll need to add them via the .
Reminders also includes an integrated search box at the upper left of its window. Search results appear in realtime as you type, with incomplete tasks listed first, with tasks due soonest listed first. Below those are matching completed tasks, oddly also listed with older due dates first--so you see completed tasks from long ago before more recent ones.
In short, Reminders on Mountain Lion is a faithful recreation of the iOS version of the app, and offers a straightforward way to add, edit, and check off todo list items. The seamless sync with your iOS devices affords the fairly simple app some serious power; typing out your shopping list on your Mac and accessing it immediately from your iPhone turns out to be pretty great.