Nope, you are using your pre-created JSGF file (with whatever ending you like — the one that ships with the sample app has the ending “.gram”) and if you don’t already have a phonetic dictionary that goes with it you can use LanguageModelGenerator to create one as I described. Then you can pass your JSGF file and the .dic file that you used LanguageModelGenerator to create to startListeningWithLanguageModelAtPath:.
As I mentioned in your other thread, JSGF is a more difficult approach because you are responsible for your own research on its requirements. There is nothing to document on the OpenEars side of things; you have to already have a JSGF file and phonetic dictionary and know what those files are (the fact that there is a hacky, unsupported way to create a .dic file using LanguageModelGenerator nonwithstanding).
OpenEars supports JSGF because it’s a common format that is used by existing speech UI designers, but it isn’t a goal of the project to introduce users to developing JSGF or its components.