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
Linphone - open source SIP client
SIP (VOIP) phoneGPL-3.0-only
VoIP.ms SMS
Popular Android messaging app for VoIP.ms, a Canadian VoIP providerApache-2.0
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 - secure calls
Protect your privacy with encrypted phone calls.GPL-2.0-or-later
aTalk
XMPP/Jabber client with encrypted instant messaging and video callsApache-2.0
PilferShush Jammer
Block unwanted use of onboard microphoneApache-2.0