macosverify
I am asking this out of curiosity. When I download an app by an unidentified developer:
1) What does it mean that the app is by an "unidentified developer"? How is a developer identified?
2) What is the Mac doing when I am opening that app for the first time and I see "Verifying.." (or something similar)?
Your computer iTunes is waiting for the iPhone to "fix itself" and clean up from the interrupted sync.
The mobile iTunes database (and I'm sure several others) will need to be rebuilt to clean up after an interrupted sync. You can see/test this by disconnecting your iOS device in the middle of podcast or music syncing. If you then immediately start up iTunes for iOS - you will get an Updating LIbrary screen while it itdbprepserver does its work. You'll get a "verifying message" until these post-sync and interrupted-sync cleanup activities finish. Once iTunes on the desktop has "verified" the phone is ready to start another sync, it commences with the normal backup and sync activities. My timing shows the interrupted recovery to take twice the time of a normal sync completion but usually less than a minute either way.
If it's your first backup in Lion, you need to leave the computer awake and connected to the Time Machine volume and let it do its thing, perhaps overnight. Once it makes an initial backup it has to construct an elaborate index database so that the Time Machine restore functions can work correctly. If you interrupt or cancel the process, it will have to start over from the beginning again at some other time, and this will indeed take up time and system resources. I have heard complaints from others that the initial backup, verifying, indexing, etc. takes a great deal of time in Lion, but you need to allot the time necessary to let the system do its thing in order that it work correctly.
Best Answer
Apple provides digital 'certificates' to registered developers, who pay $99 per year to register. Any applications signed with those certificates will be 'verified'.
It's nothing to do with the App Store as such. Registered developers can make certified apps available on their own websites.
Apple can remove the certificate from developers who are found to be shipping malware or being naughty in some other way.
When you first open an application, MacOS checks that the certificate is valid. If the app was made by a developer who is not registered with Apple, then you will get the message that the app is unknown to Apple, and therefore potentially risky. Of course, lots of very good software is written by developers who don't register with Apple.