You can create and manage to-do items or tasks for all areas of your life—such as work, home, and school—by using the Reminders app on iCloud.com from a Mac or Windows web browser. You can also share reminder lists with other iCloud users. Changes you make to reminder lists are automatically pushed to each of your iOS devices and Mac and Windows computers where you set up iCloud for Reminders (or Tasks on a Windows computer).
On your iPhone, iPad, or iPod touch, changes are pushed to the Reminders app.
On your Mac, changes are pushed to Reminders (or iCal in OS X v10.7.5).
On your Windows computer with iCloud Control Panel installed, changes appear as tasks in Microsoft Outlook.
No matter which device you use to create and manage reminders, the changes are updated everywhere.
Reminders also appear in Notification Center on iOS devices and Mac computers.
Access iCloud Reminders from a web browser
Go to Apple ID (the one you use with iCloud).
If you’re using another iCloud app, click the app’s name at the top of the iCloud.com window, then click Reminders.
When accessing iCloud Reminders, make sure you use a browser recommended in the Apple Support article iCloud: System requirements.