iOS 10 has its bugs and most of them, if not all, can be fixed by restarting your device. iOS 10.0.2 was released to deal with the bugs a restart, a hard reset, and a factory reset failed to fix. That said, all is not well with the new OS. Odd bugs plague iOS 10 with text being cut off in the Messages app, a serious battery drain issue, games running slower on slightly older devices being some of the more common ones. One problem that effects the Notes app is the missing ‘Add People’ button. The Notes app in iOS 10 lets you collaborate with other people. To collaborate on a note, there is an ‘Add People’ button next to the Share button at the very top of a note. You must tap this button if you want to add a collaborator to it. Unfortunately, not all users can see it. The solution is fairly simple. Here’s what you have to do.
Before you try anything else make sure you have iCloud enabled and the Notes app has access to it. If despite iCloud being enabled and Notes having access to it, you still don’t see the ‘Add People’ button, proceed as below.
Trin 1: Delete the Notes app. iOS 10 lets you delete stock apps like you can any other app. Simply tap and hold the Notes app icon. When it starts shaking, tap the cross button at the top left to delete it. We should warn you that this will delete all notes in the ‘On this phone’ folder. Back them up to iCloud to keep them safe.
Trin 2: Restart your phone. Do not skip this step.
Trin 3: Download the Notes app from the App Store. Make sure it has been published by Apple and you’re not installing spam on your phone,
Trin 4: Set up the Notes app. It will ask you to grant it access to iCloud. Once you’ve done so, return to the Notes app and tap the ‘Upgrade’ button.
Trin 5: Restart your device one more time for good measure. The ‘Add People’ button will start to appear next to the Share button.
This was tested on an iPhone 6 running iOS 10.0.2.