If you mean the "Find my iPhone" app on the iPhone, then I believe the answer is yes. I have it on mine and have no problem, it even shows roughly where in the house the iPhone is.
If you mean the "Find my iPhone" app on the iPhone, then I believe the answer is yes. I have it on mine and have no problem, it even shows roughly where in the house the iPhone is.
You don't need to install the app. The app is merely provided to be installed on device Y so the user can log in and track device X. In order to track device X, you must set up Find My iPhone under General --> Mail --> MobileMe (Find My iPhone is a free feature now).