Any iOS device, Mac, Apple TV, or Windows computer that works with iCloud, including:
iPhone, iPad, or iPod touch with iOS 7 or later.
You can use iCloud with iOS 6, but it doesn’t show Activity view, show video clips in shared photo streams, or let you post photos and video clips to shared photo streams other people own.
You can use iCloud with iOS 5, but it doesn’t take advantage of iCloud Photo Sharing, iCloud Tabs, Find My iPhone Lost Mode, and Find My Friends location-based alerts.
A Mac with OS X v10.8.2 or later.
You need OS X v10.9 or later and iPhoto 9.5 or Aperture 3.5 to add or view videos in shared photo streams and to see Activity view.
You can use iCloud with OS X v10.7.5, but it doesn’t take advantage of iCloud Photo Sharing, iCloud Tabs, or Find My iPhone Lost Mode.
A Windows computer that has Windows 8 or Windows 7, iCloud Control Panel 3.0 or later, and iTunes 11 or later (for iTunes in the Cloud).
Apple TV with software 6.0 or later, for viewing shared photo streams and My Photo Stream.
You can use Apple TV software 5.1, but it doesn’t show Activity view or video clips in shared photo streams.
You can use Apple TV software 5.0–5.0.2, but it doesn’t show shared photo streams.
To use iCloud features on these devices, you must set up iCloud on each device.
The Apple Support website has the latest system recommendations and requirements, including versions of apps that work with iCloud features.