Comparison

Stack Testers Flow Friend vs Ag

Price, ratings, monetisation and update history for both apps, side by side β€” with what reviewers say about each.

Head to head
About

Stack Testers Flow Friend

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
Read full description

Stack Testers Flow Friend is part of a suite of apps developed by the Engineers of CES Environmental Instruments, one of the UKs leading environmental Test Houses and incorporates some of their on-site calculations in an easy to use app. When working on the stack and you need to quickly calculate a velocity or volume flow, the answer can be at your fingertips. By inputting the essential parameters of the stack size and gas conditions, the velocity and volume flow can be determined without the need to manually calculate the value or start up a laptop. The app is an essential tool for the professional Environmental engineer. The app is a useful aid to the C & I engineer calculating the Differential Pressure cell mA output used for data logging. The contents of the CES Environmental Instruments popular Engineers Note Book is preloaded within the app.

About

Ag

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
Read full description

Ag-drive is the all-in-one agricultural platform connecting agronomy, farm management and contractors. LAMMA Founders Trophy Winner 2023 – Best Overall Innovation Designed for farmers, contractors and agronomists, Ag-drive helps businesses reduce paperwork, improve compliance and manage operations from planning through to invoicing. Whether you're managing jobs, field records, inventory, spray and fertiliser recommendations or customer invoicing, Ag-drive brings everything together in one connected system. KEY FEATURES - Job Scheduling & Live Job Tracking – Send jobs directly to operators and track progress in real time. - Field Mapping & Cropping Records – Manage field boundaries, crops and seasonal records in one place. - Inventory & Store Management – Record and monitor chemical, fertiliser, seed and product stock levels. - Spray & Fertiliser Recommendations – Create and manage agronomy recommendations with full traceability. - Soil Sampling Records – Store soil sampling locations, results and nutrient information digitally. - Farm & Contractor Connectivity – Share jobs between farms and contractors with complete visibility of work. - Timesheets – Capture employee hours quickly and accurately from any device. - Health & Safety Checks – Complete digital risk assessments and pre-start checks before work begins. - Invoicing & Accounting Integration – Generate invoices and connect with Xero, Sage and QuickBooks. - Works Offline – Continue recording information without signal and sync when back online. - Secure Cloud Storage – Access your records anytime from mobile, tablet or desktop. Available on mobile, tablet and desktop, Ag-drive keeps your team connected wherever they are. Download Ag-drive today and discover how one platform can connect agronomy, farm management and contractors.

Screenshots

Stack Testers Flow Friend4 screens
Ag4 screens

Verdict

The call

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.

Scored on Price Β· Rating Β· Positive reviews Β· Number of ratings Β· Update frequency Β· Ads Β· In-app purchases Β· Monetization Β· Best chart rank Β· Devices Β· Requires iOS

CostPrice Β· In-app purchases Β· Ads Β· Monetization

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

UpkeepUpdate frequency

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.

Scorecard3 real differences Β· 5 level
Stack Testers Flow Friend versus Ag: the parameters behind the verdict, then further details
ParameterStack Testers Flow FriendAg
PriceFreeFree
Positive reviews0.0% of reviews93.3% of reviews β€” better
Update frequencyEvery 8 monthsEvery 9 days β€” better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPod β€” betteriPhone, iPod
Requires iOS13.0 β€” better15.0
Further details β€” not scored
Size32 MB46 MB
Age rating4+4+
DeveloperLewis HolmesStudford Agtech Ltd

Customer experience

Stack Testers Flow Friend

Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

Ag

Written reviews15 reviews
Positive93.3%
Neutral0.0%
Negative6.7%

In-app purchases

None

Stack Testers Flow Friend

No in-app purchases

None

Ag

No in-app purchases

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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