# Spin vs ONI system

The clearest difference is review sentiment: Spin at 86% against ONI system's 33%. Spin also leads on iOS requirement (6.0 vs 13.0). ONI system's advantage is price (Free vs $2.99) and update cadence (every 6 weeks vs every 3 months). On ads, in-app purchases and device support there is nothing between them.

ONI system is free to download; Spin costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Spin ships an update every 3 months, ONI system every 6 weeks. The most recent releases landed on September 25, 2026 and September 14, 2026 respectively.

## The numbers

| Metric | Spin | ONI system |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | **[4.6 (44 ratings)](https://appshunter.io/ios/app/spin-a-wind/id327740080/reviews)** | — |
| Number of ratings | **44** | — |
| Positive reviews | **86.1% of reviews** | 33.3% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 6 weeks** |
| Monetization | Paid | **Free** |
| Size | 10 MB | 90 MB |
| Requires iOS | **6.0** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Len Robinson](https://appshunter.io/developer/327740083) | [NAM system a.s.](https://appshunter.io/developer/1156895479) |

## What reviewers say

### Spin

[App page](https://appshunter.io/ios/app/spin-a-wind/id327740080)

Calculate critical aviation weather data including wind components, temperature conversions, altitude calculations, and airspeed. Designed for pilots with an intuitive, one-handed interface and instant results.

**Highlights:** Wind component calculation (headwind, tailwind, crosswind), Temperature conversions and wind chill factor, Altitude calculations (pressure, density), Airspeed calculator (TAS, Mach, speed of sound), Customizable units and caution thresholds, One-handed, reel-based interface

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

**In-app purchases:** none


### ONI system

[App page](https://appshunter.io/ios/app/oni-system/id1156895480)

Access and view crucial asset data, including lists, real-time positions, and traffic information. Track trips, view routes, and get detailed asset states like temperature and battery levels. Navigate directly to asset locations.

**Highlights:** View asset lists, Real-time asset positions, Google traffic near assets, Logbook of trips, Asset route history, Navigation to asset location, Detailed asset states

**In-app purchases:** none


## Frequently asked questions

### Is Spin free?

Spin costs $2.99, with no in-app purchases.

### Is ONI system free?

ONI system is free to download, with no in-app purchases.

### Do Spin or ONI system have ads?

Neither Spin nor ONI system shows ads.

### Which is updated more often, Spin or ONI system?

Spin ships an update every 3 months, and ONI system every 6 weeks. Most recently, Spin was updated on September 25, 2026 and ONI system on September 14, 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.*