Twilio's Sync for IoT` allows real-time state synchronization on IoT devices, enabling applications like `blinking an LED in real-time`. The product is currently in Developer Preview and requires registration. Users can manage their devices as "Fleets" in the console and create a default deployment and service instance. Device authentication can be done using X.509 client certificates or key/password pairs. To use Sync, users need to create a document with a primitive like `Document` and initialize its key-value pairs. The ESP8266 Dev Board can be used to read and update documents using the `Arduino IDE`. Users can send updates to the document from the command line using `cURL`, allowing them to control the LED's state remotely. With Sync, users can build various IoT projects, such as a GPS tracker or a real-time dashboard.