The Mailbox sample illustrates the usage of Streamezzo InstantScript for managing the display and navigation within a dynamic list (here a list of messages (mailbox)).
The main purpose of such implementation is to enable performing complex operations locally on device (i.e. without requiring a connection to the server) but also to reduce the amount of data being transferred from server to client (bad user experience related to latency) and the effort to maintain such implementation (bad developer experience related to code complexity).