The ease of use, how it integrates into our app design process with minimal effort required from us as developers/designers is great! It's also very easy to implement in existing projects that don't have an SDK available yet but we will be adding one soon so I can see this being used widely by other teams now too once they've added their own tooling support (which should happen fairly quickly).
We're using gazeify primarily within Sketch where you drag & drop elements onto pages or designs…