IOS – iPad Air 2 keeps losing Continuity features, requiring restart

Deleting a downloaded app does two things:

1. Jettisons the data (like a reset for that app)
2. Allows for a clean copy of the app to be downloaded again

You could restore the entire device and test maps before restring your backup or you could back it up and erase all content and settings and then test.

Flip a coin if one of those two options does not seem better to you and feel free to ask a follow on question if you find some more details to add to the question and don't want to edit them into the existing question.

It can't be deleted it's one of the built-in apps. If you can't find it on any of your homescreens or app folders, and you can't find it via the spotlight search screen (swipe your first home screen to the right), then is it hidden by Settings > General > Restrictions > Camera being set 'off' ?

If not then have you tried a reset to see if you can find it after the iPad has restarted ? Press and hold both the sleep and home buttons for about 10 to 15 seconds (ignore the red slider), after which the Apple logo should appear - you won't lose any content, it's the iPad equivalent of a reboot.

If that doesn't find it then have you got an Exchange email account set up on the iPad ? If so then the account administrator might be hiding the Camera app - you could try removing the account and see if it re-appears.