# DirtOS vs Field Sentinel Mapper

The clearest difference is in-app purchases: Field Sentinel Mapper at none against DirtOS's 1. DirtOS's advantage is chart position (#196 vs unranked) and iOS requirement (15.6 vs 17.0). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. DirtOS sells 1 in-app purchase, starting at $49.99 per year. Field Sentinel Mapper asks for nothing beyond the download.

DirtOS ships an update fortnightly, Field Sentinel Mapper every 3 weeks. Both last shipped on October 25, 2026.

## The numbers

| Metric | DirtOS | Field Sentinel Mapper |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (3 ratings)](https://appshunter.io/ios/app/dirtos/id6757966180/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Fortnightly** | Every 3 weeks |
| Monetization | Freemium | — |
| Best chart rank | **#196** | — |
| Size | 153 MB | 168 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Sean Jeffrey Connell](https://appshunter.io/developer/1808021277) | [Tech Maven GeoSpatial LLC](https://appshunter.io/developer/1459067502) |

## What reviewers say

### DirtOS

[App page](https://appshunter.io/ios/app/dirtos/id6757966180)

**Currently charting:** #196 Top Grossing · Navigation (US App Store)

Navigate off-road and backcountry with specialized GPS tools. Import routes, receive audio cues, and track groups live, even offline. Designed for use in challenging conditions with customizable quick keys.

**Highlights:** Import GPX routes, Turn-by-turn audio navigation, Next 3 waypoints display, Quick Keys for on-the-fly waypoint marking, Live and offline group tracking, Works offline with downloaded maps, 3D flyover route preview

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PreRun Pro | $49.99 | per year |


### Field Sentinel Mapper

[App page](https://appshunter.io/ios/app/field-sentinel-mapper/id6786338407)

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

**In-app purchases:** none


## Frequently asked questions

### Is DirtOS free?

DirtOS is free to download, with in-app purchases available.

### Is Field Sentinel Mapper free?

Field Sentinel Mapper is free to download, with no in-app purchases.

### Do DirtOS or Field Sentinel Mapper have ads?

Neither DirtOS nor Field Sentinel Mapper shows ads.

### Which is updated more often, DirtOS or Field Sentinel Mapper?

DirtOS ships an update fortnightly, and Field Sentinel Mapper every 3 weeks. Most recently, DirtOS was updated on October 25, 2026 and Field Sentinel Mapper 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.*