How to fix damaged app message on macOS Sierra
To resolute Gatekeeper issues on macOS Sierra and unlock images and programs ( annoying image/application is damaged messages pretending you cannot open things ).
For that reason you might have to completely disable Gatekeeper checks, and to do that open your terminal and type:
sudo spctl --master-disable
Your mac password will be required.
For Mac OS X 10.11 or later read this
NMac Ked Team