Sipdroid

A SIP (VOIP) clientGPL-3.0-only

Recover VOIP settings from H300s

Retrieve VOIP Settings from Sercomm H300s as shipped from Vodafone Greece.GPL-3.0-or-later

VoIP.ms SMS

Send and read SMS via voip.msApache-2.0

Linphone - open source SIP client

SIP (VOIP) phoneGPL-3.0-only

baresip

VoIP User Agent app for Android based on baresip SIP libraryBSD-3-Clause

baresip+

VoIP User Agent app for Android based on baresip SIP libraryBSD-3-Clause

Element - Secure Messenger

Group messenger - encrypted messaging, group chat and video callsApache-2.0

SIP Switch

Access Internet call settingsGPL-3.0-only

Simlar - free and secure calls

Encrypted and free phone calls over the internetGPL-2.0-or-later

PilferShush Jammer

Block unwanted use of onboard microphoneApache-2.0