Comparison

Stack Testers Friend vs Aliver

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

Head to head
About

Stack Testers Friend

This mobile toolkit provides essential on-site calculations for stack testers. Quickly perform gas conversions, probe position calculations, and other vital engineering tasks without needing a laptop. It's designed for environmental engineers needing immediate access to data while working in the field.

Highlights
  • Gas conversion calculations
  • Isokinetic sample position calculations
  • Extraction rate calculations
  • Gas density calculations
  • Particulate matter normalization
  • Calibration function calculations
Features
Read full description

The app has been 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 one easy to use app. When working on the stack and you need that quick answer to a gas conversion or probe position, the answer can be at your fingertips. Simple and easy to use the app contains lots of essential calculations for the stack tester without the need to manually calculate the value or start up a laptop. The app is an essential tool for the professional Environmental engineer having all the tools to quickly check the numbers whilst out and around site. The contents of the CES Environmental Instruments popular Engineers Note Book is preloaded within the app. The app can do the following and much more: - Calculate Dia, CSA, Circ. - Isokinetic sample positions, General & Tangential - Extraction rates - Gas density - Calculate H20 from wet & dry Oxygen - Gas ppm/mg/m³ conversions & Normalisation - LOD - Particulate Matter Normalisation & estimation of temp, H2O & O2 - Ranging & scaling of dust monitors & outputs - Calculation of values using calibration functions - Biomass fuels

About

Aliver

This app helps you reduce screen time and build healthier digital habits without deleting your favorite applications. It offers features like app blocking, screen time tracking, and daily routines to help you focus, reduce stress, and improve sleep.

Highlights
  • Reduce screen time
  • App blocking
  • Screen time tracking
  • Build mindful habits
  • Daily routines
  • Focus deeper
Features
Read full description

Take back control of your time with Aliver Aliver helps you reduce screen time, stay focused, and build healthier digital habits — without deleting your favorite apps. The average person spends 6 hours a day on their phone. That’s almost a full day every single week. Aliver is here to help you reclaim that time and invest it in what truly matters — your goals, your people, your peace of mind. With Aliver, you can: - Save 2+ hour every day - Focus deeper and longer - Reduce stress and feel more present - Sleep better and improve your daily rhythm - Build mindful phone habits that actually stick Why Aliver works: App Blocking: Block distracting apps at specific times or after reaching your daily limit. Screen Time Tracking: Get clear, real-time insights into how you use your phone. Daily Routines: Automate limits based on your work, rest, or sleep schedule. Aliver isn’t about quitting your phone. It’s about using it on your terms. Start your journey toward a more focused and intentional life today. Terms and Conditions: https://docs.google.com/document/d/e/2PACX-1vQgitwnCvT3j8Zq8BGEdtZlant2tWoYRkpfVcYwI1DMVzZNsJ1XoHDb0SW8Dtw3wg/pub Privacy Policy: https://docs.google.com/document/d/e/2PACX-1vT2ZMFcRKzK4DSkjwyuUpOxFXi8lwIn27-eJ8CmQvh6kA1Ew0fICsZvITvVVI4kXQ/pub

Screenshots

Stack Testers Friend4 screens
Aliver4 screens

Verdict

The call

The clearest difference is review sentiment: Stack Testers Friend at 100% against Aliver's 22%. Stack Testers Friend also leads on in-app purchases (none vs 6) and ads (none vs shown). Aliver's advantage is update cadence (monthly vs every 7 months). On price there is nothing between them.

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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Aliver sells 6 in-app purchases, starting at $5.99 per 7 days. Stack Testers Friend asks for nothing beyond the download.

UpkeepUpdate frequency

Stack Testers Friend ships an update every 7 months, Aliver monthly. The most recent releases landed on September 24, 2026 and October 12, 2026 respectively.

Scorecard7 real differences · 3 level
Stack Testers Friend versus Aliver: the parameters behind the verdict, then further details
ParameterStack Testers FriendAliver
PriceFreeFree
Rating—4.8 (1.4K ratings) — better
Positive reviews100.0% of reviews — better21.7% of reviews
Number of ratings—1.4K — better
Update frequencyEvery 7 monthsMonthly — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS13.0 — better17.0
Further details — not scored
Size33 MB44 MB
Age rating4+4+
DeveloperLewis HolmesReface Europe UAB

Customer experience

Stack Testers Friend

Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Aliver

All ratings1,363 ratings
Positive94.3%
Neutral3.0%
Negative2.7%
Written reviews23 reviews
Positive21.7%
Neutral13.0%
Negative65.2%

Bugs and requests

Stack Testers Friend

Not enough reviews yet to summarise bugs or requests.

Aliver

Reported bugs

3 issues
  • Couldn't get past pay wall
  • Couldn't even get into the app
  • Paywall issues

Requested features

1 request
  • Make an app more people can use without paying

In-app purchases

None

Stack Testers Friend

No in-app purchases

6 purchases

Aliver

Subscriptions6
  • Aliver PRO$5.997 Days
  • Aliver PRO$8.997 Days
  • Aliver PRO$14.991 Month
Show 3 more
  • Aliver PRO$44.991 Year
  • Aliver PRO$59.991 Year
  • Aliver PRO3 Days trial$69.991 Year

Questions

Is Stack Testers Friend free?
Stack Testers Friend is free to download, with no in-app purchases.
Is Aliver free?
Aliver is free to download, with in-app purchases available.
Do Stack Testers Friend or Aliver have ads?
Aliver shows ads; Stack Testers Friend does not.
Which is updated more often, Stack Testers Friend or Aliver?
Stack Testers Friend ships an update every 7 months, and Aliver monthly. Most recently, Stack Testers Friend was updated on September 24, 2026 and Aliver on October 12, 2026.

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