I know. And I usally get these kinds of popups only once per app
(or dmg) but like I mentioned, I get this popup about ScreenSync
every time I restart or log in. And every time I click on
Open. Only with ScreenSync, not with other applications.
Got a solution?
I'm running ScreenSync on a brand new clean installed MacBook
OS X should have flagged after you clicked open. You can remove
the quarantine flag manually. Open Terminal and paste the following
command : sudo xattr -r -d com.apple.quarantine