A SIP app for Android is a software application that allows users to make and receive voice over IP (VoIP) calls using the Session Initiation Protocol (SIP). SIP is a signaling protocol that is used to establish, maintain, and terminate VoIP calls. SIP apps for Android are typically used in conjunction with a SIP service provider, which provides the necessary infrastructure to support VoIP calls. SIP apps for Android offer a number of benefits over traditional phone calls, including lower cost, improved call quality, and increased flexibility.
SIP apps for Android have become increasingly popular in recent years as the cost of VoIP services has declined and the quality of VoIP calls has improved. Today, there are a number of different SIP apps available for Android, each with its own unique features and capabilities. Some of the most popular SIP apps for Android include Zoiper, CSipSimple, and Linphone.