Apps like CallThru.us

Here are some great alternatives to CallThru.us by Desktop Communications :
Groundwire: VoIP SIP Softphone
Groundwire: VoIP SIP Softphone
★3.4
Acrobits: VoIP SIP Softphone
Acrobits: VoIP SIP Softphone
★4.0
AGEphone
AGEphone
★5.0
MAXSIP
MAXSIP
★3.9
Simplifi Scout
Simplifi Scout
★4.2
Mabrook Plazma
Mabrook Plazma
★3.5
ZoiperBeta
ZoiperBeta
★4.0
HelloSpoke Mobile
HelloSpoke Mobile
★4.0
SmartPhone
SmartPhone
★4.3
mTalk
mTalk
★4.2
Unity-Mobile
Unity-Mobile
★3.6
Speed Dial
Speed Dial
★3.3
HelloByte Dialer
HelloByte Dialer
★3.9
Wildix Collaboration Mobile
Wildix Collaboration Mobile
★4.3
Phone - Dialer & iCall Screen
Phone - Dialer & iCall Screen
★4.2
Contacts: Phone Calls & Dialer
Contacts: Phone Calls & Dialer
★4.2