Apps like REDCOM Sigma Client

Here are some great alternatives to REDCOM Sigma Client by REDCOM Laboratories :
Sipnetic
Sipnetic
★4.0
Bria Mobile: VoIP Softphone
Bria Mobile: VoIP Softphone
★4.1
Acrobits: VoIP SIP Softphone
Acrobits: VoIP SIP Softphone
★3.8
Groundwire: VoIP SIP Softphone
Groundwire: VoIP SIP Softphone
★3.4
SessionTalk Pro Softphone
SessionTalk Pro Softphone
★3.2
SessionTalk Softphone
SessionTalk Softphone
★3.5
PortSIP Softphone
PortSIP Softphone
★3.7
AGEphone
AGEphone
★5.0
MizuDroid SIP VOIP Softphone
MizuDroid SIP VOIP Softphone
★4.1
SessionCloud SIP Softphone
SessionCloud SIP Softphone
★3.6
Zoiper IAX SIP VOIP Softphone
Zoiper IAX SIP VOIP Softphone
★4.4
Connect.US
Connect.US
★4.2
jiPBX - SIP VOIP Softphone
jiPBX - SIP VOIP Softphone
★4.0
Mabrook Plazma
Mabrook Plazma
★3.5
ZoiperBeta
ZoiperBeta
★4.0
Teo Softphone for Android
Teo Softphone for Android
★4.8