The Interop external object which can be found under the folder Smar Device API provides several methods to interact with the device where the app is executing.
The ClearCache method enables you to clear the cache on the device; the next interaction with the application server will retrieve all the information again.
To use it, you just need to add the following in any action associated to a Smart Devices object:
Done! When the button ClearAll on the SDPanel is tapped all cached information on the device will be cleared, the next interaction with the server side will retrieve all information again, including the variables default values.