# Flow Rate Conversion vs Lambda Tuner

The clearest difference is rating: Lambda Tuner at 3.3 against Flow Rate Conversion's 3.0. Lambda Tuner also leads on ratings volume (3 vs 1). Flow Rate Conversion's advantage is price ($2.99 vs $3.99) and iOS requirement (13 vs 16.6). On update cadence, ads, in-app purchases and monetization model there is nothing between them.

Flow Rate Conversion costs $2.99 and Lambda Tuner $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Lambda Tuner holds the better App Store score, 3.3 against 3.0. Both are backed by a comparable volume of ratings — 1 and 3 respectively.

Flow Rate Conversion ships an update every 29 months, Lambda Tuner every 19 months. The most recent releases landed on September 13, 2026 and July 5, 2026 respectively.

## The numbers

| Metric | Flow Rate Conversion | Lambda Tuner |
| --- | --- | --- |
| Price | **$2.99** | $3.99 |
| Rating | [3.0 (1 ratings)](https://appshunter.io/ios/app/flow-rate-conversion/id525300855/reviews) | **[3.3 (3 ratings)](https://appshunter.io/ios/app/lambda-tuner/id632731065/reviews)** |
| Number of ratings | 1 | **3** |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 29 months | **Every 19 months** |
| Monetization | Paid | Paid |
| Size | 1 MB | 1 MB |
| Requires iOS | **13** | 16.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Nitrio](https://appshunter.io/developer/321121189) | [Johan Bjors](https://appshunter.io/developer/632731068) |

## What reviewers say

### Flow Rate Conversion

[App page](https://appshunter.io/ios/app/flow-rate-conversion/id525300855)

Easily convert between various units of flow rate, including volume-based, mass-based, and mole-based measurements. Essential for physics and engineering applications involving fluid dynamics and hydrometry.

**Highlights:** Volume flow rate conversion, Mass flow rate conversion, Mole-based flow rate conversion, Physics and engineering utility, Fluid dynamics calculations

**Features:** macOS Compatibility

**In-app purchases:** none


### Lambda Tuner

[App page](https://appshunter.io/ios/app/lambda-tuner/id632731065)

This tool helps tune PID controllers using the Lambda method to calculate P, I, and D parameters. It's designed for intuitive use in various process industries and works on self-regulating and integrating loops. You can also use it to learn the impact of different PID parameters.

**Highlights:** Lambda method for PID parameter calculation, Supports self-regulating and integrating loops, Intuitive and easy to use interface, Adjustable Lambda value for reaction speed, Manual PID parameter testing, Educational tool for PID parameter impact

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Flow Rate Conversion free?

Flow Rate Conversion costs $2.99, with no in-app purchases.

### Is Lambda Tuner free?

Lambda Tuner costs $3.99, with no in-app purchases.

### Which has better reviews, Flow Rate Conversion or Lambda Tuner?

Lambda Tuner is rated higher. Flow Rate Conversion averages 3.0 out of 5 from 1 ratings, while Lambda Tuner averages 3.3 from 3 ratings.

### Do Flow Rate Conversion or Lambda Tuner have ads?

Neither Flow Rate Conversion nor Lambda Tuner shows ads.

### Which is updated more often, Flow Rate Conversion or Lambda Tuner?

Flow Rate Conversion ships an update every 29 months, and Lambda Tuner every 19 months. Most recently, Flow Rate Conversion was updated on September 13, 2026 and Lambda Tuner on July 5, 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.*