# Stack Testers Flow Friend vs Ag

The clearest difference is review sentiment: Ag at 93% against Stack Testers Flow Friend's 0%. Ag also leads on update cadence (every 9 days vs every 8 months). Stack Testers Flow Friend's advantage is iOS requirement (13.0 vs 15.0). On price, ads, in-app purchases and monetization model there is nothing between them.

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

Stack Testers Flow Friend ships an update every 8 months, Ag every 9 days. The most recent releases landed on October 5, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | Stack Testers Flow Friend | Ag |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 0.0% of reviews | **93.3% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 8 months | **Every 9 days** |
| Monetization | Free | Free |
| Size | 32 MB | 46 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Lewis Holmes](https://appshunter.io/developer/1454834389) | [Studford Agtech Ltd](https://appshunter.io/developer/1553045013) |

## What reviewers say

### Stack Testers Flow Friend

[App page](https://appshunter.io/ios/app/stack-testers-flow-friend/id1454834655)

This mobile toolkit assists environmental engineers with on-site calculations for stack testing. Quickly determine velocity and volume flow by inputting stack size and gas conditions, eliminating the need for manual calculations or laptops. It also aids in calculating differential pressure cell mA output for data logging.

**Highlights:** Velocity and volume flow calculations, Input stack size and gas conditions, Differential pressure cell mA output calculation, Preloaded Engineers Note Book content, On-site calculation tool

**Features:** macOS Compatibility

**In-app purchases:** none


### Ag

[App page](https://appshunter.io/ios/app/ag-drive/id1553045011)

This app streamlines farm management by eliminating paperwork for agricultural contractors and farmers. It facilitates job recording, invoicing, and integrates with accounting software, improving efficiency and cash flow. It also offers features like telematic job tracking, field mapping, and health and safety assessments.

**Highlights:** Telematic job recording, Customizable job operations, Product lists for jobs, Farm/contractor relationship management, Field mapping, Digital timesheets, Invoicing and accounting integration

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

**In-app purchases:** none


## Frequently asked questions

### Is Stack Testers Flow Friend free?

Stack Testers Flow Friend is free to download, with no in-app purchases.

### Is Ag free?

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

### Do Stack Testers Flow Friend or Ag have ads?

Neither Stack Testers Flow Friend nor Ag shows ads.

### Which is updated more often, Stack Testers Flow Friend or Ag?

Stack Testers Flow Friend ships an update every 8 months, and Ag every 9 days. Most recently, Stack Testers Flow Friend was updated on October 5, 2026 and Ag on October 10, 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.*