# Propeller Calc vs Abyss Battery

The clearest difference is rating: Abyss Battery at 5.0 against Propeller Calc's 3.0. Abyss Battery also leads on update cadence (every 8 months vs every 21 months) and ratings volume (3 vs 1). On price, ads, in-app purchases and monetization model there is nothing between them.

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

Abyss Battery holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 1 and 3 respectively.

Propeller Calc ships an update every 21 months, Abyss Battery every 8 months. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Propeller Calc | Abyss Battery |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.0 (1 ratings)](https://appshunter.io/ios/app/propeller-calc/id478119478/reviews) | **[5.0 (3 ratings)](https://appshunter.io/ios/app/abyss-battery/id1579033829/reviews)** |
| Number of ratings | 1 | **3** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 21 months | **Every 8 months** |
| Monetization | Free | Free |
| Size | 3 MB | 8 MB |
| Requires iOS | 17.0 | **11.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Frode Rørvik](https://appshunter.io/developer/478119481) | [Abyss Battery, Inc.](https://appshunter.io/developer/1594681469) |

## 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


### Abyss Battery

[App page](https://appshunter.io/ios/app/abyss-battery/id1579033829)

Monitor your battery's live status, including voltage and amp consumption, via a wireless app interface. Diagnose battery health with Bluetooth reports and track charging habits and usage history, such as completed life cycles.

**Highlights:** Live battery status monitoring, Bluetooth diagnostic reports, Charging control and monitoring, Battery history and life cycle tracking, Wireless app interface

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Propeller Calc free?

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

### Is Abyss Battery free?

Abyss Battery is free to download, with no in-app purchases.

### Which has better reviews, Propeller Calc or Abyss Battery?

Abyss Battery is rated higher. Propeller Calc averages 3.0 out of 5 from 1 ratings, while Abyss Battery averages 5.0 from 3 ratings.

### Do Propeller Calc or Abyss Battery have ads?

Neither Propeller Calc nor Abyss Battery shows ads.

### Which is updated more often, Propeller Calc or Abyss Battery?

Propeller Calc ships an update every 21 months, and Abyss Battery every 8 months. Most recently, Propeller Calc was updated on November 1, 2026 and Abyss Battery on November 3, 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.*