Castel SIP vs STN UC
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Castel SIP
This application functions as a SIP intercom softphone, enabling users to make and receive audio and video calls from IP intercom stations on their mobile devices. It allows for communication and remote door opening, working through Wi-Fi and cellular data networks.
- Audio and video calls
- IP intercom station integration
- Remote door opening
- Address book with favorites
- Call history
- Remote commands during calls
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Castel SIP App is a SIP intercom softphone. The easy-to-use and intuitive application, allows you to make and receive audio and video calls from IP intercom stations (XELLIP, CAPIP...) on your iPhone or iPad. With Castel SIP App, you can communicate and open the door, anywhere. It works with the Castel Cloud SIP server through Wi-Fi and 3G/4G/5G. Main features: - Audio and video calls with advanced functionalities (Loudspeaker, transfer calls, hold...) - Address book with favorites - Call history - Remote commands during calls and DTMF - Support landscape and portrait mode for all smartphone and tablet designs (camera notch...) Note: Please, check your cellular operator's terms of agreement to make sure they allow SIP calls on their network before using Castel SIP App.
STN UC
This application functions as a SIP-based softphone, enabling users to make and receive calls and instant messages over Wi-Fi or cellular data. It integrates with a specific PBX system to support push notifications for incoming calls and messages, even when the app is not actively running.
- SIP-based softphone
- Wi-Fi or 4G/LTE calls
- Instant messaging
- Push notifications for calls
- Push notifications for messages
- Interworks with PortSIP PBX
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STN-UC is a SIP-based softphone for iPhone that uses Wi-Fi or 4G/LTE connection to make and receive calls and Instant Messages. Interworking with PortSIP PBX, STN-UC support push notification, which allows it receive calls and messages even it was force terminated.
Screenshots
Verdict
The clearest difference is review sentiment: Castel SIP at 60% against STN UC's 0%. STN UC's advantage is iOS requirement (11.0 vs 15.5). On price, update cadence, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Castel SIP ships an update every 4 months, STN UC every 2 months. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.
| Parameter | Castel SIP | STN UC |
|---|---|---|
| Price | Free | Free |
| Positive reviews | 60.0% of reviews — better | 0.0% of reviews |
| Update frequency | Every 4 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 15.5 | 11.0 — better |
| Further details — not scored | ||
| Size | 84 MB | 54 MB |
| Age rating | 4+ | 4+ |
| Developer | Castel | PortSIP Solutions, Inc. |
Customer experience
Castel SIP
STN UC
In-app purchases
Castel SIP
No in-app purchases
STN UC
No in-app purchases
