# SoSIM vs Slow Letters (Slow Reply)

The clearest difference is update cadence: Slow Letters (Slow Reply) at fortnightly against SoSIM's every 3 months. Slow Letters (Slow Reply) also leads on iOS requirement (13.0 vs 15.6). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

SoSIM ships an update every 3 months, Slow Letters (Slow Reply) fortnightly. The most recent releases landed on November 11, 2026 and November 9, 2026 respectively.

## The numbers

| Metric | SoSIM | Slow Letters (Slow Reply) |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (4 ratings)](https://appshunter.io/ios/app/sosim/id1558388399/reviews)** | — |
| Number of ratings | **4** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Fortnightly** |
| Monetization | Free | — |
| Size | 47 MB | 22 MB |
| Requires iOS | 15.6 | **13.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Hutchison Telephone Company Limited](https://appshunter.io/developer/292047326) | [闻欣 黄](https://appshunter.io/developer/1891292006) |

## What reviewers say

### SoSIM

[App page](https://appshunter.io/ios/app/sosim/id1558388399)

Manage your Hong Kong prepaid SIM card services, including data usage, top-ups, and plan changes. This app allows you to switch between local and travel data, apply for number portability, and access support.

**Highlights:** Enquire data usage and SIM expiry, Purchase Hong Kong/Travel data packages, Instant top-up functionality, Mobile Number Portability (MNP) application, eSIM and new number exchange, Link to MoneyBack rewards, Manage Real Name Registration

**Features:** macOS Compatibility

**In-app purchases:** none


### Slow Letters (Slow Reply)

[App page](https://appshunter.io/ios/app/slow-letters-slow-reply/id6761828276)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is SoSIM free?

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

### Is Slow Letters (Slow Reply) free?

Slow Letters (Slow Reply) is free to download, with no in-app purchases.

### Do SoSIM or Slow Letters (Slow Reply) have ads?

Neither SoSIM nor Slow Letters (Slow Reply) shows ads.

### Which is updated more often, SoSIM or Slow Letters (Slow Reply)?

SoSIM ships an update every 3 months, and Slow Letters (Slow Reply) fortnightly. Most recently, SoSIM was updated on November 11, 2026 and Slow Letters (Slow Reply) on November 9, 2026.

---

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