# NSRI SafeTrx vs GridVolt

The clearest difference is iOS requirement: NSRI SafeTrx at 11.0 against GridVolt's 15.0. 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.

Both ship on a similar rhythm, roughly every 5 months. The most recent releases landed on November 1, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | NSRI SafeTrx | GridVolt |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (35 ratings)](https://appshunter.io/ios/app/nsri-safetrx/id953494702/reviews)** | — |
| Number of ratings | **35** | — |
| Positive reviews | 72.7% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | Every 5 months |
| Monetization | Free | — |
| Size | 35 MB | 20 MB |
| Requires iOS | **11.0** | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [National Sea Rescue Institute of South Africa](https://appshunter.io/developer/953494701) | [SolrBoost Pty Ltd](https://appshunter.io/developer/1667247561) |

## What reviewers say

### NSRI SafeTrx

[App page](https://appshunter.io/ios/app/nsri-safetrx/id953494702)

This app helps maritime adventurers plan and track their journeys. Users can register vessel details, file trip plans with ETAs and crew numbers, and activate emergency calls. It also offers a quick 'Track only' mode and stores trip history in a mobile logbook.

**Highlights:** Vessel and journey registration, Sail Plan mode with ETA and crew details, Track only mode for quick tracking, Emergency call activation (iPhone only), Mobile Logbook with trip replay, Personalized trip planning checklist

**Features:** macOS Compatibility

**In-app purchases:** none


### GridVolt

[App page](https://appshunter.io/ios/app/gridvolt/id6478967181)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is NSRI SafeTrx free?

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

### Is GridVolt free?

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

### Do NSRI SafeTrx or GridVolt have ads?

Neither NSRI SafeTrx nor GridVolt shows ads.

### Which is updated more often, NSRI SafeTrx or GridVolt?

NSRI SafeTrx ships an update every 5 months, and GridVolt every 5 months. Most recently, NSRI SafeTrx was updated on November 1, 2026 and GridVolt on October 25, 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.*