You can model your iPhone application using Tersus on any platform, but the final stage of creating a native version which is to be installed on an iPhone requires xCode (an Apple tool which is only available on the Mac).
More details on the procedure are provided in http://www.tersus.com/#Id=2820.
Note that an alternate approach is to create your application as a web-based mobile app - i.e. installed on a Tersus Server, and accessed through the mobile device's browser (iPhone's mobile safari or Android's browser), and providing the look and feel of a mobile app - see http://www.tersus.com/#Id=3283.
For best results, use the Firefox browser..