There is some tips on how to get in running in the manual.
"Running OSX 10.10.4 (Yosemite) on MacBook Pro from 2010, when I try to open the app, it says: 'The application "FPVFreerider" can't be opened"
1. If you unzip the file on a Windows machine and transfer the file to your mac with a USB stick it should work.
2. Better solution for anybody else who has this problem. OS X is picky about which programs can be run (the first time) by double-clicking. To run a program that says "this can't be opened", right-click the icon and choose "Open". You'll be given an option to open the program, and from then on it won't bug you.
3. For Mac's having trouble installing FPV Freerider try going to the Mac's System Preferences>Security and Privacy> General Tab and check the box "Anywhere" to see if this allows your Mac to install FPV Freerider.
4. For anybody who is still having the issue of the simulator not opening on OSX 10 - you need to open up terminal and type sudo chmode +x (fpvfreerider.app) and that should do it.
(For FPV Freerider Recharged that should be sudo chmod +x ~/Applications/FPVFreerider_Recharged.app )