# GSM vs Primis Mobile

The clearest difference is rating: Primis Mobile at 5.0 against GSM's 2.3. GSM's advantage is update cadence (every 2 months vs every 9 months) and iOS requirement (7.0 vs 15.6). On price, ratings volume, 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.

Primis Mobile holds the better App Store score, 5.0 against 2.3. Both are backed by a comparable volume of ratings — 3 and 4 respectively.

GSM ships an update every 2 months, Primis Mobile every 9 months. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | GSM | Primis Mobile |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.3 (3 ratings)](https://appshunter.io/ios/app/gsm-relay/id595567537/reviews) | **[5.0 (4 ratings)](https://appshunter.io/ios/app/primis-mobile/id1482003352/reviews)** |
| Number of ratings | 3 | **4** |
| Positive reviews | 16.7% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 9 months |
| Monetization | Free | Free |
| Size | 3 MB | 21 MB |
| Requires iOS | **7.0** | 15.6 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [艳丽 刘](https://appshunter.io/developer/595252190) | [Identiv, Inc.](https://appshunter.io/developer/655015409) |

## What reviewers say

### GSM

[App page](https://appshunter.io/ios/app/gsm-relay/id595567537)

Control industrial devices remotely via SMS commands. This application allows users to send text messages to a specific GSM-RELAY unit for remote operation and parameter configuration. Requires a WAFER GSM-RELAY hardware unit to function.

**Highlights:** Seven channels remote control, Send SMS for remote control, Remote parameter configuration, Industrial control applications, Requires WAFER GSM-RELAY unit

**Features:** macOS Compatibility

**In-app purchases:** none


### Primis Mobile

[App page](https://appshunter.io/ios/app/primis-mobile/id1482003352)

Manage your access control system remotely. Lock or unlock doors, set schedules, and monitor system status from your mobile device.

**Highlights:** Remote lock/unlock, Schedule access, Check system status, Mobile access control

**In-app purchases:** none


## Frequently asked questions

### Is GSM free?

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

### Is Primis Mobile free?

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

### Which has better reviews, GSM or Primis Mobile?

Primis Mobile is rated higher. GSM averages 2.3 out of 5 from 3 ratings, while Primis Mobile averages 5.0 from 4 ratings.

### Do GSM or Primis Mobile have ads?

Neither GSM nor Primis Mobile shows ads.

### Which is updated more often, GSM or Primis Mobile?

GSM ships an update every 2 months, and Primis Mobile every 9 months. Most recently, GSM was updated on November 1, 2026 and Primis Mobile on November 3, 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.*