Since ios and mac os x are objective c programming languages so with this backend work with mac osx

I want to develop an app for mac os x so that people can use the app on they’re macbooks and imacs, can i just follow the ios sdk?

Hello,

Yes, definitely. Simply follow the instructions for Mac OS X setup here:
https://backendless.com/documentation/users/ios/users_requirements.htm

and then use the same APIs we document for iOS.

Regards,
Mark