Quarantino will allow you review a download (like Skype) and if so desired, remove the quarantine flags so that the application can be run, normally.
LINK TO QUARANTINO
Gatekeeper is a wonderful security feature of Mac OS X. But with the restrictions in 10.10, 10.9 and 10.8.5 on older, valid codesigned applications, a quarantine removal tool is useful. I recently downloaded the latest version of Skype, only to learn that I had to remove it from quarantine using an arcane command line tool.
Recommended for all!