# Castel SIP vs 1

The clearest difference is iOS requirement: 1 at 6.0 against Castel SIP's 15.5. On price, update cadence, ads and in-app purchases there is nothing between them.

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, 1 every 5 months. The most recent releases landed on September 18, 2026 and October 14, 2026 respectively.

## The numbers

| Metric | Castel SIP | 1 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/1-talk/id639536802/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 60.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 4 months** | Every 5 months |
| Monetization | Free | Free |
| Size | 84 MB | 23 MB |
| Requires iOS | 15.5 | **6.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Castel](https://appshunter.io/developer/566301834) | [PortSIP Solutions, Inc.](https://appshunter.io/developer/426903821) |

## What reviewers say

### Castel SIP

[App page](https://appshunter.io/ios/app/castel-sip/id566301831)

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.

**Highlights:** Audio and video calls, IP intercom station integration, Remote door opening, Address book with favorites, Call history, Remote commands during calls

**Features:** macOS Compatibility

**In-app purchases:** none


### 1

[App page](https://appshunter.io/ios/app/1-talk/id639536802)

Make affordable international calls using your mobile device over Wi-Fi or 3G. Receive VoIP calls anywhere with push notifications or background mode support. This service is designed for iPhone, iPad, and iPod Touch.

**Highlights:** Affordable international calls, Wi-Fi and 3G calling, Receive VoIP calls, Push notifications for incoming calls, iOS background mode support

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Castel SIP free?

Castel SIP is free to download, with no in-app purchases.

### Is 1 free?

1 is free to download, with no in-app purchases.

### Do Castel SIP or 1 have ads?

Neither Castel SIP nor 1 shows ads.

### Which is updated more often, Castel SIP or 1?

Castel SIP ships an update every 4 months, and 1 every 5 months. Most recently, Castel SIP was updated on September 18, 2026 and 1 on October 14, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*