Popcorn Time is of course also available for Mac OS X but installation requires bypassing Gatekeeper. Gatekeeper is a native OS X feature to prevent accidental installation of potentially harmful software.
It prevents unintentional installation of apps downloaded anywhere else than Apple’s own App Store. Since Popcorn Time for obvious reasons isn’t in there, Gatekeeper has to be bypassed if you want to install any of the Popcorn Time apps on your Mac.
Double clicking the installer makes a dialogue box appear displaying the message Popcorn Time can’t be opened because it is from an unidentified developer. This is Gatekeeper doing its job and the only option is to close the box without installing the program.
Fortunately, Gatekeeper isn’t meant to be ironclad so you can both very easily and safely bypass it. So in order to install Popcorn Time (or iOS installer) on your Mac this is the only way to do it.
Popcorn Time is generally considered safe to install (but still illegal to use) so you shouldn’t be afraid of getting viruses, malware etc.