Systems and methods for providing additional functions on a user equipment (UE) with an over-the-top (OTT) application are disclosed. The systems and methods can enable the UE to register with a telephony application server (TAS) using a subscriber identity module identification (SIM ID). The registration can enable communications directed to a cellular number, for example, to be redirected to the UE via a Wi-Fi connection through a wireless residential gateway (WRG). The OTT application can enable the UE to utilize the SIM ID to send and receive communications via a cellular network, an internet protocol (IP) network, or both. The OTT application can also provide applications and capabilities that are not otherwise available on the UE. An OTT settings graphical user interface (GUI) can enable the user to dynamically configure how communications are sent and received in response to changing conditions or preferences.