# SHv4 Calculator vs Tech

The clearest difference is review sentiment: SHv4 Calculator at 67% against Tech's 13%. SHv4 Calculator also leads on rating (5.0 vs 1.6). Tech's advantage is ratings volume (87 vs 4) and update cadence (monthly vs every 3 months). 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.

SHv4 Calculator holds the better App Store score, 5.0 against 1.6. That said, the two scores are not equally well evidenced: Tech has 87 ratings behind it against 4, so its average is the more settled of the two. Written reviews point the same way: 67% of SHv4 Calculator's written reviews are positive against 13% of Tech's.

SHv4 Calculator ships an update every 3 months, Tech monthly. The most recent releases landed on October 24, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | SHv4 Calculator | Tech |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (4 ratings)](https://appshunter.io/ios/app/shv4-calculator/id979817071/reviews)** | [1.6 (87 ratings)](https://appshunter.io/ios/app/tech-air-app/id1504440133/reviews) |
| Number of ratings | 4 | **87** |
| Positive reviews | **66.7% of reviews** | 13.1% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Monthly** |
| Monetization | Free | Free |
| Size | 1 MB | 151 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [HealTech Electronics Ltd.](https://appshunter.io/developer/979817070) | [ALPINESTARS SPA](https://appshunter.io/developer/1499986821) |

## What reviewers say

### SHv4 Calculator

[App page](https://appshunter.io/ios/app/shv4-calculator/id979817071)

Calculate your vehicle's speedometer error and get setup instructions for a SpeedoHealer module. This free, ad-free tool helps correct inaccurate speed and odometer readings on most motorcycles and some cars. It offers troubleshooting information and is compatible with non-cable driven speedometers.

**Highlights:** Calculate speedometer error, Generate SpeedoHealer v4 setup instructions, Access troubleshooting information, Ad-free experience, Offline functionality, Compatible with most motorcycles and cars

**In-app purchases:** none


### Tech

[App page](https://appshunter.io/ios/app/tech-air-app/id1504440133)

Easily register and monitor your motorcycle airbag system's status and battery life. Track ride details, record location and speed, and relive your journeys with detailed maps and statistics. Build a library of your rides and manage system settings.

**Highlights:** Register Tech-Air® 5 Airbag System, Monitor system status and battery life, Track ride details with location and speed, Record and visualize ride statistics, Build a library of recorded rides, Disable system for off-road riding, Update system firmware

**Features:** macOS Compatibility

**In-app purchases:** none

**What reviewers like**

- ✅ Successful firmware updates when working properly
- 📍 Ride tracking and route recording functionality
- 🔋 Battery level monitoring
- ⚡ Quick pairing when conditions are optimal
- 🎯 Simple and intuitive UI design

**What reviewers complain about**

- 🐛 Constant disconnection issues between app and vest
- 📡 Extremely limited Bluetooth range (requires phone within 5cm of vest)
- 🔐 Registration and verification SMS not received in multiple regions
- ❌ Firmware update failures stuck at 2-3%
- ⚠️ App crashes on startup after updates

**Reported bugs**

- App crashes immediately upon launch after updates
- Firmware update stuck at 2% indefinitely
- Error 12 during firmware installation
- Verification SMS not arriving (especially for +420 Czech numbers and other regions)
- QR code scanner not recognizing codes

**Requested features**

- PC/desktop application for firmware updates
- Lean angle tracking and display
- Maximum speed recording in ride logs
- Acceleration metrics in ride data
- Altitude data in ride tracking


## Frequently asked questions

### Is SHv4 Calculator free?

SHv4 Calculator is free to download, with no in-app purchases.

### Is Tech free?

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

### Which has better reviews, SHv4 Calculator or Tech?

SHv4 Calculator is rated higher. SHv4 Calculator averages 5.0 out of 5 from 4 ratings, while Tech averages 1.6 from 87 ratings.

### Do SHv4 Calculator or Tech have ads?

Neither SHv4 Calculator nor Tech shows ads.

### Which is updated more often, SHv4 Calculator or Tech?

SHv4 Calculator ships an update every 3 months, and Tech monthly. Most recently, SHv4 Calculator was updated on October 24, 2026 and Tech on October 21, 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.*