Castel SIP vs M1 Messenger
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.
M1 Messenger
This app offers a versatile communication platform, combining SIP calling, walkie-talkie functionality, and location sharing. Connect with users nearby, track family locations, and integrate with IP PBX systems for broader calling capabilities.
- SIP client with push notifications
- Walkie-Talkie mode (Push-To-Talk)
- Users Nearby discovery
- Family Locator
- PSTN/GSM calling
- IP PBX integration
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All-in-One M1 Messenger - calls to any PSTN or GSM numbers, Walkie-Talkie, SIP client and more. - SIP client with push notification feature. - Users Nearby — you can see users around you (up to a 100 km radius). Chat with people nearby and make new friends. - Family Locator - get location your family members or friends. - Push-To-Talk. Use this Walkie-Talkie mode in group and regular chats. - SIP equipment — connect you IP PBX (for example, Asterisk), call center or any IP phone or gateway to connect with any M1 user directly from your PBX, call center or IP phone.
Screenshots
Verdict
The clearest difference is review sentiment: Castel SIP at 60% against M1 Messenger's 0%. M1 Messenger's advantage is update cadence (every 3 weeks vs every 4 months) and iOS requirement (9.0 vs 15.5). On price, ads, in-app purchases and monetization model 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, M1 Messenger every 3 weeks. The most recent releases landed on November 1, 2026 and November 4, 2026 respectively.
| Parameter | Castel SIP | M1 Messenger |
|---|---|---|
| Price | Free | Free |
| Rating | — | 1.0 (1 ratings) — better |
| Positive reviews | 60.0% of reviews — better | 0.0% of reviews |
| Number of ratings | — | 1 — better |
| Update frequency | Every 4 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.5 | 9.0 — better |
| Further details — not scored | ||
| Size | 84 MB | 79 MB |
| Age rating | 4+ | 17+ |
| Developer | Castel | Melliton |
Customer experience
Castel SIP
M1 Messenger
In-app purchases
Castel SIP
No in-app purchases
M1 Messenger
No in-app purchases
Questions
Is Castel SIP free?
Is M1 Messenger free?
Do Castel SIP or M1 Messenger have ads?
Which is updated more often, Castel SIP or M1 Messenger?
Other comparisons
