Groundwire: the SIP softphone for your PBX or VoIP provider
Groundwire is a SIP softphone app from Acrobits, a leader in VoIP and communication software since 2009. It delivers clear voice and video calls for personal and professional use, with an interface built for daily calling and none of the clutter.
IMPORTANT, PLEASE READ
Groundwire is a SIP client, not a VoIP service. You need service from a VoIP provider or PBX that supports standard SIP clients.
Business calling features
Groundwire carries the call handling you expect from a desk phone:
- Group calls, for conferencing several people into one conversation. - Attended transfers, so you can announce a caller before handing the call over. - Unattended transfers, when the caller just needs the right extension. - Voicemail with notifications, so a missed call still reaches you. - Instant messaging, for the things that do not need a call. - Per-account settings, so one device carries several SIP identities cleanly.
Works with your PBX or VoIP provider
Groundwire is a universal client and true VoIP for PBX users. Teams run it as an Asterisk softphone, a FreePBX extension, or a 3CX endpoint, and it connects just as readily to hosted PBX systems and business phone providers. It also comes preconfigured for major providers, so setup takes minutes. Because it is a standard client, there is no lock-in: bring the account you already have, and Groundwire becomes the mobile extension of your PBX, with encrypted SIP calling on every network.
On a team it is the business softphone dialer sitting on top of the PBX you already pay for. On your own it keeps a work line separate, or carries a desk extension in your pocket.
Key features of the softphone
- Audio on widely used codecs, Opus, G.729 and G.711 among them. - Video calls at 720p HD, carried by H.264 and VP8. - Private conversations with military-grade encryption, including TLS, SRTP, and ZRTP. - Low battery use thanks to efficient push notifications. - The VoIP dialer hands calls over between WiFi and mobile data without dropping them. - Custom call settings and ringtones per account. - 5G ready and compatible with most mobile operating systems.
Enjoy calls that feel like a natural part of your Android phone. Groundwire works with Android's built-in calling features for a smooth, familiar experience, and routes audio intelligently between your phone, speaker, wired headset and connected Bluetooth devices. With your permission, it can also add Groundwire calls to the Phone app's Recents list, so your call history stays easy to find in one place.
A softphone app without the fees
Groundwire is a softphone for calling over WiFi and mobile data, with the business dialer features that usually cost a monthly fee. One payment, no subscription, nothing hidden: buy it once and it stays yours. Encryption sits inside that price rather than on top of it.
Run a call center, manage a fleet of extensions, or keep a dependable sip phone for a home office. The same app covers all of it, without extra tiers.
Download Groundwire and put a dependable SIP dialer on your phone, with Acrobits engineering and responsive support behind it.
A softphone app with seamless SIP calling and an intuitive VoIP dialer
Updated on
Sep 29, 2026
Communication
Data safety
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Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
just started having issues in the last few days. It doesn't remember my output choice so every call I need to tell it to comment to my headset. I also no longer hear the 'try' or Ring - just silence until AFTER the call is picked up. That's right, the first few seconds are cut off after someone answers. It makes me feel very unprofessional. This all was working better last week. I use VoIP.ms
4 people found this review helpful
Acrobits, s.r.o.
September 22, 2026
We’re aware of the recent ringback issue, and an Android update with a fix should be available soon. If the headset/output issue continues after that, please contact us at support@acrobits.net so we can take a closer look.
Mike Giarrusso
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July 17, 2026
I have used this for several months now to manage my business numbers, everything was great 5 stars.. Then all of a sudden it can not verify my birthday in google. I have filled out the information several times and restarted the app. Now all i get when opening the app is the age verification. The app is useless now I cannot manage any numbers. Very disappointed I really like the app!
9 people found this review helpful
Acrobits, s.r.o.
July 23, 2026
Hi Mike, thanks for the kind words and sorry for the disruption. The age check is a new legal age-assurance requirement, not adult content. Please update Groundwire and your Google Play Store and Play services, then restart and retry. If it still won't clear, contact acrobits.net/support with your app and Play versions. We'll be happy to help.
Bob
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September 16, 2026
Mysteriously the colours in SMS for the text are dark blue on black, after an upgrade, and I don't see any way to fix it. It's literally unusable and unreadable.
3 people found this review helpful
Acrobits, s.r.o.
September 22, 2026
Thanks for reporting this. We’re aware of the issue and plan to address it in an upcoming update. We appreciate your patience.
What’s new
- Added a new setting to enable or disable the DND switch - Fixed ringback behavior - Fixed several crashes and improved stability - Fixed notification badge updates - Improved audio performance - Improved call handling, including second calls, forwarding, and outgoing call redirection - Improved call screen reliability and call integration