# Decon Field Guide vs FAST

The clearest difference is ads: FAST at none against Decon Field Guide's shown. FAST also leads on monetization model (free vs ad-supported) and iOS requirement (12.1 vs 15.1). Decon Field Guide's advantage is rating (4.6 vs 4.3) and update cadence (every 2 months vs every 7 months). On price, review sentiment, ratings volume 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.

Decon Field Guide holds the better App Store score, 4.6 against 4.3. Both are backed by a comparable volume of ratings — 8 and 3 respectively. Written reviews split almost evenly too, at 0% and 0% positive.

Decon Field Guide ships an update every 2 months, FAST every 7 months. The most recent releases landed on June 4, 2026 and June 1, 2026 respectively.

## The numbers

| Metric | Decon Field Guide | FAST |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (8 ratings)](https://appshunter.io/ios/app/decon-field-guide/id1388378944/reviews)** | [4.3 (3 ratings)](https://appshunter.io/ios/app/fast-act/id1446010360/reviews) |
| Number of ratings | **8** | 3 |
| Positive reviews | 0.0% of reviews | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | **Every 2 months** | Every 7 months |
| Monetization | Ad-supported | **Free** |
| Size | 73 MB | 22 MB |
| Requires iOS | 15.1 | **12.1** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [First Line Technology, LLC](https://appshunter.io/developer/1388378943) | [Timilon Technology Acquisitions LLC](https://appshunter.io/developer/1446010359) |

## What reviewers say

### Decon Field Guide

[App page](https://appshunter.io/ios/app/decon-field-guide/id1388378944)

This reference app provides quick and efficient decontamination methods for hundreds of threats. It features a classic Threat Index, pictorial instructions, and an in-app dwell timer to guide users through mission execution. Designed for approved users, it aims to make anyone an instant decontamination expert.

**Highlights:** Threat Index for decontamination methods, Pictorial instructions, In-app dwell timer, Covers hundreds of threats, Designed for approved users

**Features:** macOS Compatibility

**In-app purchases:** none


### FAST

[App page](https://appshunter.io/ios/app/fast-act/id1446010360)

This app serves as a guide for HAZMAT professionals on how a specific decontamination agent interacts with and neutralizes various chemicals. It features a comprehensive chemical threat index, detailing efficacy on vapor releases and contaminated surfaces, with search and sort functionalities.

**Highlights:** Extensive chemical threat index, FAST-ACT efficacy details, Vapor release decontamination, Contaminated surface decontamination, Search by Chemical Name, Sort by CAS Number

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Decon Field Guide free?

Decon Field Guide is free to download, with no in-app purchases.

### Is FAST free?

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

### Which has better reviews, Decon Field Guide or FAST?

Decon Field Guide is rated higher. Decon Field Guide averages 4.6 out of 5 from 8 ratings, while FAST averages 4.3 from 3 ratings.

### Do Decon Field Guide or FAST have ads?

Decon Field Guide shows ads; FAST does not.

### Which is updated more often, Decon Field Guide or FAST?

Decon Field Guide ships an update every 2 months, and FAST every 7 months. Most recently, Decon Field Guide was updated on June 4, 2026 and FAST on June 1, 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.*