# JB4 Mobile vs CarTest

The clearest difference is price: CarTest at Free against JB4 Mobile's $27.99. CarTest also leads on rating (4.2 vs 3.8) and update cadence (monthly vs every 3 months). JB4 Mobile's advantage is in-app purchases (none vs 3) and ads (none vs shown). On review sentiment, device support and iOS requirement there is nothing between them.

CarTest is free to download; JB4 Mobile costs $27.99 up front. CarTest sells 3 in-app purchases, starting at $3.99 per 3 months. JB4 Mobile asks for nothing beyond the download.

CarTest holds the better App Store score, 4.2 against 3.8. That said, the two scores are not equally well evidenced: JB4 Mobile has 239 ratings behind it against 13, so its average is the more settled of the two. Written reviews complicate that: 52% of JB4 Mobile's written reviews are positive against 44% of CarTest's, so the app with the better star average is not the one people write more warmly about.

JB4 Mobile ships an update every 3 months, CarTest monthly. The most recent releases landed on November 1, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | JB4 Mobile | CarTest |
| --- | --- | --- |
| Price | $27.99 | **Free** |
| Rating | [3.8 (239 ratings)](https://appshunter.io/ios/app/jb4-mobile/id794841332/reviews) | **[4.2 (13 ratings)](https://appshunter.io/ios/app/cartest-performance-tester/id1534136951/reviews)** |
| Number of ratings | **239** | 13 |
| Positive reviews | **52.4% of reviews** | 44.4% of reviews |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 3 months | **Monthly** |
| Monetization | **Free** | Free with in-app purchases |
| Best chart rank | **#4** | — |
| Size | 24 MB | 8 MB |
| Requires iOS | 15.1 | **15.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Dmac Mobile Developments, LLC](https://appshunter.io/developer/372235786) | [Takao Ichimura](https://appshunter.io/developer/1474061593) |

## What reviewers say

### JB4 Mobile

[App page](https://appshunter.io/ios/app/jb4-mobile/id794841332)

**Currently charting:** #4 Top Paid · Sports, #171 Top Paid (US App Store)

This app acts as a mobile data logger and display for vehicles equipped with a JB4 tuner. It allows users to monitor and log various engine parameters, view data in real-time, and adjust settings for performance tuning.

**Highlights:** Live gauge monitoring, Data logging and graphing, User adjustable settings, WMI settings modification, On-the-fly map switching, Code reading and deletion

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

**In-app purchases:** none

**What reviewers like**

- 🚀 Great app and a must have with the JB4
- 🔒 Robust security features
- 👍 Awesome data logging
- 👍 Incredible Support
- 👍 Works as expected

**What reviewers complain about**

- 🐛 Doesn't work properly, screen upside down and backwards
- 🐛 Stopped working after update
- 🐛 Bluetooth connection issues
- 🐛 Gauges freezing
- 🐛 Screen turns off

**Reported bugs**

- App crashes
- Can't connect to server
- Mirrored/inverted display
- Compatibility issues with new iOS versions
- Trouble logging in

**Requested features**

- Add CarPlay support
- Allow customizing map names
- Add more gauge styling options
- Improve UI and layout
- Integrate with Apple Carplay


### CarTest

[App page](https://appshunter.io/ios/app/cartest-performance-tester/id1534136951)

Measure your vehicle's acceleration performance with this tool. Easily track times like 0-60 mph or 0-1/4 mile. Useful for performance testing and safe driving awareness on public roads.

**Highlights:** Measure 0-60 mph and 0-1/4 mile times, Track acceleration on public roads, Repeatable measurements with Start/Sensing, Countdown start with false start detection, View and share previous results, Selectable speed units (km/h or mph)

**Features:** Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Feature enhancements | $3.99 | per 3 months |
| Feature enhancements | $5.99 | per year |
| Feature enhancements | $9.99 | one-time |


## Frequently asked questions

### Is JB4 Mobile free?

JB4 Mobile costs $27.99, with no in-app purchases.

### Is CarTest free?

CarTest is free to download, with in-app purchases available.

### Which has better reviews, JB4 Mobile or CarTest?

CarTest is rated higher. JB4 Mobile averages 3.8 out of 5 from 239 ratings, while CarTest averages 4.2 from 13 ratings.

### Do JB4 Mobile or CarTest have ads?

CarTest shows ads; JB4 Mobile does not.

### Which is updated more often, JB4 Mobile or CarTest?

JB4 Mobile ships an update every 3 months, and CarTest monthly. Most recently, JB4 Mobile was updated on November 1, 2026 and CarTest on October 29, 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.*