# Propeller Calc vs One Touch Tow Lite

The clearest difference is update cadence: One Touch Tow Lite at every 8 months against Propeller Calc's every 21 months. One Touch Tow Lite also leads on iOS requirement (13.0 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.

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

Propeller Calc ships an update every 21 months, One Touch Tow Lite every 8 months. The most recent releases landed on September 26, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | Propeller Calc | One Touch Tow Lite |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.0 (1 ratings)](https://appshunter.io/ios/app/propeller-calc/id478119478/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 21 months | **Every 8 months** |
| Monetization | Free | — |
| Size | 3 MB | 23 MB |
| Requires iOS | 17.0 | **13.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Frode Rørvik](https://appshunter.io/developer/478119481) | [Radical Engineering, LLC](https://appshunter.io/developer/1501509291) |

## What reviewers say

### Propeller Calc

[App page](https://appshunter.io/ios/app/propeller-calc/id478119478)

This utility calculates propeller performance metrics like pitch, gear ratio, RPM, slip, and speed. Input any four values, and the app computes the fifth, helping users understand the relationship between propeller design and boat performance.

**Highlights:** Calculate pitch, gear ratio, RPM, slip, and speed, Enter any four variables to find the fifth, Understand propeller slip and its impact, Supports iPhone and iPad, Free to use

**Features:** macOS Compatibility

**In-app purchases:** none


### One Touch Tow Lite

[App page](https://appshunter.io/ios/app/one-touch-tow-lite/id6748350761)

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

**In-app purchases:** none


## Frequently asked questions

### Is Propeller Calc free?

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

### Is One Touch Tow Lite free?

One Touch Tow Lite is free to download, with no in-app purchases.

### Do Propeller Calc or One Touch Tow Lite have ads?

Neither Propeller Calc nor One Touch Tow Lite shows ads.

### Which is updated more often, Propeller Calc or One Touch Tow Lite?

Propeller Calc ships an update every 21 months, and One Touch Tow Lite every 8 months. Most recently, Propeller Calc was updated on September 26, 2026 and One Touch Tow Lite on October 28, 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.*