There’s this great little website that very few Apple users seem to know about. It helps you keep track of all of Apple systems uptime and downtime. I discovered this months ago and decided to use it just now when I realized that my App Store and iTunes Store were not working properly on my iPhone.
At time of posting, the page was showing issues with App Store, iBooks Store, iTunes Store, Mac App Store, iCloud Mail and iCloud account sign-in.
While the site doesn’t give ETAs for when things will be back up and running, it only takes 5 seconds to check in and see what’s happening.