# Propeller Vibration vs String search calculator

The clearest difference is price: String search calculator at Free against Propeller Vibration's $23.99. String search calculator also leads on update cadence (every 2 weeks vs every 43 months). Propeller Vibration's advantage is ads (none vs shown) and iOS requirement (12.0 vs 15.8.3). On in-app purchases and device support there is nothing between them.

String search calculator is free to download; Propeller Vibration costs $23.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Propeller Vibration ships an update every 43 months, String search calculator every 2 weeks. The most recent releases landed on October 12, 2026 and October 3, 2026 respectively.

## The numbers

| Metric | Propeller Vibration | String search calculator |
| --- | --- | --- |
| Price | $23.99 | **Free** |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 43 months | **Every 2 weeks** |
| Size | 9 MB | 37 MB |
| Requires iOS | **12.0** | 15.8.3 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [DOAO Consulting AB](https://appshunter.io/developer/1181701800) | [Hideaki Uchikoshi](https://appshunter.io/developer/1559575002) |

## What reviewers say

### Propeller Vibration

[App page](https://appshunter.io/ios/app/propeller-vibration/id1216065698)

**In-app purchases:** none


### String search calculator

[App page](https://appshunter.io/ios/app/string-search-calculator/id6502218395)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Propeller Vibration free?

Propeller Vibration costs $23.99, with no in-app purchases.

### Is String search calculator free?

String search calculator is free to download, with no in-app purchases.

### Do Propeller Vibration or String search calculator have ads?

String search calculator shows ads; Propeller Vibration does not.

### Which is updated more often, Propeller Vibration or String search calculator?

Propeller Vibration ships an update every 43 months, and String search calculator every 2 weeks. Most recently, Propeller Vibration was updated on October 12, 2026 and String search calculator on October 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.*