Descriptions : Groundwire, the leading business SIP client, is now available for Android. Groundwire offers all the functions a business user needs and makes it child's play to take your office management with you wherever you go. Check out all of these great features, more to come soon.
Features :

+ Multi-line
+ Call conference
+ Transfer and Attended Transfer
+ Voicemail
+ Call forwarding
+ Bluetooth headset support
+ Secure calls via SRTP (SDES)
+ Support for use in WiFi and 3G networks
+ Fast import of accounts from large VoIP providers
+ HD broadband audio via G.722 and Opus codecs
+ TLS support for encrypted SIP
+ simple, intuitive configuration
+ Add new contacts directly from Groundwire
+ Handsfree support
+ detailed call list
+ configurable RTP port range
+ SIP proxy support

Required Android Versions : Lollipop [5.0–5.0.2] - Marshmallow [6.0 - 6.0.1] - Nougat [7.0 – 7.1.1] - Oreo [8.0-8.1]

Download Groundwire v5.2.22 APK Paid Free

Groundwire_5.2.22.apk