Overview

The mobile app works with Asterisk, FreePBX, FreeSWITCH and any SIP PBX that can provision an extension. Siperb’s proxy uses Apple APNs or Google FCM to wake the app and deliver calls when it is backgrounded, locked or restarted. That makes incoming calls more practical on a mobile device, but Proxy Registration Mode is the only mobile registration option, and it is required for push notifications.

For PBXs and ITSPs, Siperb supports outbound registration, outbound trunk and inbound registration connections. Web and desktop clients can also connect directly to a WebRTC-capable PBX through WebSocket Registration Mode, without Siperb in the call path. This gives mixed deployments more connection choices, although it does not remove the proxy requirement on mobile.

Key features

Mobile supports audio and video calls, attended and blind transfer, three-way conference, DTMF, call history, CDR and buddy presence. That covers routine extension use and common call-handling needs, rather than limiting the app to basic calling. The mobile feature set specifies end-to-end encryption using TLS and DTLS-SRTP, a meaningful safeguard for calls.

A single account works across web, Windows, macOS, Linux, iOS and Android, with call history, contacts and settings shared across platforms. That continuity suits users who move between desk and mobile clients. A documented REST API and permanent tokens for external backend systems also give administrators a route to integrate Siperb with their own services, though the product is positioned for end users and IT administrators rather than only developers.

Siperb provides separate developer embedding and reseller co-branding resources. Its cloud-hosted components cannot be installed on a customer’s own servers; organizations that require self-hosting should consider its open-source Browser Phone instead.

Pricing

The Personal plan is free. It has limited storage, seven days of SIP Trace Logs and Register Activity Log, community support and no technical support. That is a reasonable starting point for personal use or a small evaluation, but short log retention and the lack of technical help make it a weaker fit for teams that need operational support or longer troubleshooting history.

Business costs £2.00 per month per domain user, billed monthly, and extends both log types to six months with technical support. It is the practical step up for organizations that need help resolving technical issues or must retain logs beyond a week. Business Pro costs £5.00 per month per domain user, billed monthly, and extends both log types to 12+ months, also with technical support. It suits teams for whom longer log history justifies the higher per-user cost.

Free support covers general questions with an approximately 48-hour response; paid support covers technical issues with an approximately 24-hour response. Those response windows and the distinction between general and technical help matter when deciding whether Personal is adequate. The plans are billed per domain user, so the monthly total grows with the number of users.

Platforms

Siperb supports Android, iOS, Linux, macOS, web and Windows. Mobile and desktop apps and browser calling give users options across phones and computers, while shared contacts, settings and call history help preserve continuity between them.

Who it's for

Siperb is a strong fit for individuals and organizations that already have a SIP PBX and want its extensions on mobile as well as desktop or web. Administrators who value broad PBX compatibility, cross-platform account data, call-handling features and longer log retention on paid tiers have clear reasons to consider it.

It is less suitable for organizations that require mobile registration independent of Siperb’s proxy, or that need to install Siperb’s cloud components on their own servers. Personal users who depend on technical support or extended logs may also find the free plan too constrained.

Pros and cons

Pros: Works with major named PBXs and other SIP systems that can provision an extension, giving existing deployments broad compatibility.
Pros: Push delivery can wake the app when it is locked or backgrounded, addressing a central practical need for mobile calling.
Pros: Shared history, contacts and settings across six platform types support switching between mobile, desktop and web clients.
Pros: Paid tiers add technical support and extend both log types to six months or 12+ months, providing clearer operational coverage.
Cons: Mobile has only Proxy Registration Mode, and push notifications require it; teams seeking a direct mobile-to-PBX registration option will need another fit.
Cons: Personal limits log retention to seven days, offers only community support and excludes technical support.
Cons: Cloud-hosted components cannot be self-hosted, which rules out Siperb itself for organizations with that deployment requirement.

Alternatives

Softphone and calling apps is a broader place to compare options. Blink is worth considering for a free softphone across Android, iOS, Linux, macOS, web and Windows; its free Linux, Mac and Windows downloads require a SIP account. Linphone is the alternative to consider when an open-source client that can be integrated under the GNU GPLv3 license is the priority, with proprietary licensing available for closed-source use.

SipPulse Softphone offers a free app plan for iOS, Android, Windows and Linux with unlimited users and installations, making it relevant when that stated user and installation allowance matters. Aria may suit personal, non-commercial use where unlimited calls, multi-account support and core softphone features are the draw of its free plan. Zoiper is another option for non-commercial use, with a free Windows, macOS and Linux plan limited to one account and two lines.

Bria Solo fits personal non-commercial users who can work within one device, one SIP/VoIP account and limited weekly calls on its free plan. MicroSIP is the narrower choice for a free Windows desktop SIP softphone under GPL v2. PortSIP Softphone may fit users seeking a free calling option in the Android, iOS or Windows platform range.

Verdict

Choose Siperb Mobile Softphone if you want to extend an existing SIP PBX to mobile while keeping call history, contacts and settings aligned across devices. Broad PBX compatibility, push delivery and a capable mobile call set make it a considered choice, with Business and Business Pro adding longer logs and technical support. Look elsewhere if mobile registration must bypass Siperb’s proxy or self-hosting is essential.

	Groundwire	Siperb Mobile Softphone
Free plan	No	Yes
Free trial	No	No
Paid from	—	£2/mo
Open source	No	No
Platforms	Android, iOS	Android, iOS, Linux, macOS, Web, Windows

Groundwire vs Siperb Mobile Softphone

Groundwire

Siperb Mobile Softphone