Reminders is a useful new todo app in iOS 5 with its location aware alerts and iCloud support. You can view your reminders on all iOS devices and on Mac OS X Lion.
There is no Reminders app for OS X Lion. Instead Apple has taken the todo lists found inside the old iCal and change it to be Reminders. It is not so obvious at first as Reminders by default is not shown on iCal’s main window.
In order to view the same Reminders as in your iOS devices, you need to enable iCloud on OS X Lion. This feature is not available on OS X Snow Leopard as OS X Lion is the minimum OS X for iCloud.
Next, under System Preferences->iCloud, check the “Calendars” to enable iCloud sync. And wait for a moment for the sync to complete.
To view Reminders on iCal, select from menu View->View Reminders or toggle Reminders on/off using Option Command T. Reminders will appear as a right side pane on the main iCal window.
To create a reminder, right click on the Reminders pane for a popup menu and select “New Reminder”. Or press the Command-K key. Check off reminder by clicking on the checkbox. Command-Delete to remove reminder. And double click on a reminder to bring up the edit window.