Propeller Calc vs GuavaDrop
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Propeller Calc
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.
- 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
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This calculator can determine pitch, gear ratio, RPM, propeller slip and speed parameters. Enter any four variables, and it will calculate the fifth. Use the toggle switch to choose which field to calculate. Pitch is the theoretical forward movement for one complete turn of the propeller. Every inch of the boat in contact with the water induces drag. Therefore, the distance travelled differs since the propeller is "slipping" behind the theoretical distance it should travel with each rotation. The difference between theory and reality is called slip. Depending on your application, slip typically ranges between 5% and 20%. A lower number is only sometimes what you are after. Slip of a prop changes with operating conditions and is not a direct measure of efficiency. Please consult professionals for guidance. Happy powerboating
GuavaDrop
Easily scan, create, and manage QR codes. View QR code content as text messages for convenient access. Designed for both personal and business productivity.
- Scan QR codes
- Create QR codes
- Save QR codes
- View QR code content as text
- Personal productivity
- Business productivity
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GuavaDrop lets you manage QR codes with a useful selection of features. In addition to basic features such as scanning, saving and creating QR codes, you can conveniently view the content of QR codes as text messages. GuavaDrop is especially designed for personal and business productivity. Give it a try today!
Screenshots
Verdict
The clearest difference is rating: GuavaDrop at 5.0 against Propeller Calc's 3.0. GuavaDrop also leads on update cadence (every 6 weeks vs every 21 months) and iOS requirement (15.0 vs 17.0). On price, ratings volume, ads and in-app purchases 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
GuavaDrop holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively.
Propeller Calc ships an update every 21 months, GuavaDrop every 6 weeks. The most recent releases landed on September 26, 2026 and October 16, 2026 respectively.
| Parameter | Propeller Calc | GuavaDrop |
|---|---|---|
| Price | Free | Free |
| Rating | 3.0 (1 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 1 | 1 |
| Update frequency | Every 21 months | Every 6 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 3 MB | 2 MB |
| Age rating | 4+ | 4+ |
| Developer | Frode Rørvik | Azukipan IT Solutions LLC |
Customer experience
Propeller Calc
GuavaDrop
In-app purchases
Propeller Calc
No in-app purchases
GuavaDrop
No in-app purchases
Questions
Is Propeller Calc free?
Is GuavaDrop free?
Which has better reviews, Propeller Calc or GuavaDrop?
Do Propeller Calc or GuavaDrop have ads?
Which is updated more often, Propeller Calc or GuavaDrop?
Other comparisons
