小电台 is a utility program available on iPhone that allows users to create their own channels on a world map. With a broadcasting radius of 100KM, FM channels can reach a wide audience, while AM channels enable global listeners on the same frequency. Users can also listen to messages sent by others on the same channel.

The program features a "Signal Adjuster" where users can modify the range of received signals:

• LOW: Receives messages only from the current channel.
• MID: Receives messages within a ± 5 range of the current channel.
• HIGH: Receives the full frequency range of the current mode (AM or FM).

The signal adjustment does not affect the range of messages you send.