Hello AlishaM,
Thank-you for your question.
Basically you are right, today there are no software testing tools in the market which are able to test applications installed on a UnixLinuxMACMobileetc OS (All environments except Windows OS), except of a single tool and this is the Zap-Fix for functional testing (And the ZapGen for performance testing).
Only using the mentioned testing tools you will be able to test any type of application (Web based, OS based) in any type of software environment.
These tools can answer all issues which other known testing tools encounter.
Although Zap-fix works as an add-in for HP QTP, meaning, its required OS is a Windows, using its out-of-the-box Viewers (And basically any type of remote access to the application) can be used to test the required application in its native environment.
This is done by scanning the UI of the AUT (Application Under Test) into Zap-fix, which creates an image of the UI, using the position of the objects in the scanned UI image Zap-fix is able to force its own build-in methods into the scanned UI through HP QTP.
For more understanding how Zap-fix works please contact Zap to get Zap-fix Evaluation License to try it upon other OS based applications.
Thanks,
Sasha