What if we hacked the weather app the same we Google Maps was hacked for outside-US navigation? Simply replace the data from the Chinese website with data from, say, AccuWeather. Intercept the requests so the app 'thinks' it's downloading info from that site, but not really it's being gathered from a US site and put in whatever format the app accepts the data in. The app has a database of cities and lat/long coordinates for them. We could either inject other cities into the db, which has been done successfully (though it results in an error, as the Chinese website doesn't have weather data for other cities), or, more simply, delete everything but one fake city in the db for all lat/long coordinates, and redirect the request for weather data to a local file containing information on the user's actual current location, built by a simple script.
Am I making any sense, or just rambling?