Comparison

Linear Interpolation Master vs 4

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

Head to head
About

Linear Interpolation Master

This tool simplifies linear interpolation calculations for industrial commissioning engineers. It features large, easily readable numbers for field use and allows for quick swapping of coordinate systems, such as converting between 4-20mA and 0-100% scales.

Highlights
  • Large number display for field visibility
  • Quickly swap X and Y coordinates
  • 4-20mA to 0-100% conversion
  • 0-100% to 4-20mA conversion
Features
Read full description

A linear interpolation calculator designed for industrial commissioning engineers. It has the following features: - Displays large numbers for when you are out in the field commissioning. - Allows quickly swapping x and y coordinates; for example from 4-20mA -> 0-100% to 0-100% -> 4-20mA.

About

4

This utility app converts between 4-20 mA current signals and temperature readings. It's designed for engineers and technicians to quickly check transmitter scaling, verify loop values, and troubleshoot signal issues in various industrial applications.

Highlights
  • Two-way current to temperature conversion
  • Custom min/max process range
  • Support for negative temperatures
  • Celsius and Fahrenheit support
  • Fast and clean interface
Features
Read full description

4-20 Temperature Calculator is a practical tool for engineers, technicians, and field service professionals working with 4-20 mA transmitters. Use it to quickly convert: • 4-20 mA to temperature • Temperature to 4-20 mA The app helps you work faster in the field by giving you a simple and accurate way to check transmitter scaling, verify loop values, and troubleshoot signal readings. Key features: • Two-way conversion between current and temperature • Custom min/max process range • Support for negative temperature ranges • Celsius and Fahrenheit input/output • Fast, clean interface for everyday use • Useful for HVAC, process control, maintenance, and commissioning work Whether you are calibrating a transmitter, checking a loop, or validating process values, 4-20 Temperature Calculator gives you the numbers you need in seconds.

Screenshots

Linear Interpolation Master3 screens
43 screens

Verdict

The call

The clearest difference is rating: Linear Interpolation Master at 4.7 against 4's 3.0. Linear Interpolation Master also leads on ratings volume (176 vs 2) and update cadence (every 5 months vs every 11 months). 4's advantage is in-app purchases (none vs 3) and ads (none vs shown). On price and device support 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. Linear Interpolation Master sells 3 one-off in-app purchases. 4 asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Linear Interpolation Master holds the better App Store score, 4.7 against 3.0. That said, the two scores are not equally well evidenced: Linear Interpolation Master has 176 ratings behind it against 2, so its average is the more settled of the two.

UpkeepUpdate frequency

Linear Interpolation Master ships an update every 5 months, 4 every 11 months. The most recent releases landed on September 22, 2026 and September 10, 2026 respectively.

Scorecard7 real differences · 3 level
Linear Interpolation Master versus 4: the parameters behind the verdict, then further details
ParameterLinear Interpolation Master4
PriceFreeFree
Rating4.7 (176 ratings) — better3.0 (2 ratings)
Positive reviews62.5% of reviews—
Number of ratings176 — better2
Update frequencyEvery 5 months — betterEvery 11 months
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS11.0 — better15.6
Further details — not scored
Size16 MB30 MB
Age rating4+4+
DeveloperVERVE TECHNOLOGIES PTY. LTD.Mantas Kamarauskas

Customer experience

Linear Interpolation Master

All ratings176 ratings
Positive92.6%
Neutral2.8%
Negative4.5%
Written reviews8 reviews
Positive62.5%
Neutral25.0%
Negative12.5%

4

All ratings2 ratings
Positive50.0%
Neutral0.0%
Negative50.0%

In-app purchases

3 purchases

Linear Interpolation Master

One-time3
  • Generous Tip$2.99
  • Massive Tip$3.99
  • Amazing Tip$4.99
None

4

No in-app purchases

Questions

Is Linear Interpolation Master free?
Linear Interpolation Master is free to download, with in-app purchases available.
Is 4 free?
4 is free to download, with no in-app purchases.
Which has better reviews, Linear Interpolation Master or 4?
Linear Interpolation Master is rated higher. Linear Interpolation Master averages 4.7 out of 5 from 176 ratings, while 4 averages 3.0 from 2 ratings.
Do Linear Interpolation Master or 4 have ads?
Linear Interpolation Master shows ads; 4 does not.
Which is updated more often, Linear Interpolation Master or 4?
Linear Interpolation Master ships an update every 5 months, and 4 every 11 months. Most recently, Linear Interpolation Master was updated on September 22, 2026 and 4 on September 10, 2026.

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