JB4 Mobile vs FastR
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
JB4 Mobile
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.
- Live gauge monitoring
- Data logging and graphing
- User adjustable settings
- WMI settings modification
- On-the-fly map switching
- Code reading and deletion
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The brand new JB4 Mobile application is finally ready for public release and has lots of great new features including: *Gauge theme customizations *Built-in raw CSV data viewer *Revamped User Adj./WMI data editors *New modern UI completely rewritten from the ground up *More seamless integration with our backend servers JB4 Connect Kit Users: 1) Install the Connect Kit per the installation guide for your vehicle 2) Create your account/sign in with this app 3) Ensure JB4 Mobile has all requested permissions 4) Tap the Connect button in JB4 Mobile About The App: JB4 Mobile is a mobile data logger and display for use with the JB4 tuner from Burger Motorsports. JB4 Mobile allows you to monitor and log multiple parameters from your JB4 equipped car. Parameters such as boost, rpm, fuel trims, air/fuel ratios, ignition advance and much more are available. Current Features: Live gauges Data logging Data graphing Log export via email Code reading/deletion Modify User Adj. (boost, fuel, etc.) settings Modify WMI settings Switch maps on the fly Auto WOT logging JB4 Firmware Updating JB4 ® is a registered trademark of Burger Motorsports Inc ® and is used with written permission.
FastR
Measure your vehicle's acceleration performance with this app. It automatically tests 0-60 and quarter-mile times with millisecond accuracy. Compete with others on a real-time leaderboard and save results for different car models.
- Hands-free, automated acceleration testing
- 0-60 and Quarter mile time measurement
- Millisecond accuracy
- Real-time user ranking
- Save times for different car models
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FastR is the #1 vehicle acceleration performance app in the game! Test your vehicle's 0-60 and Quarter mile times, in a hands-free, fully automated manner. You can also post your acceleration times to our leaderboard to earn bragging rights. - Features accuracy to the millisecond - Displays your rank amongst other users in real time - Lets you save acceleration times from different car models See how your vehicle's acceleration performance compares with others.
Screenshots
Verdict
The clearest difference is price: FastR at Free against JB4 Mobile's $27.99. FastR also leads on rating (4.4 vs 3.8). JB4 Mobile's advantage is in-app purchases (none vs 2) and review sentiment (52% vs 38%). On ratings volume, update cadence, ads and device support 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
FastR is free to download; JB4 Mobile costs $27.99 up front. FastR sells 2 one-off in-app purchases. JB4 Mobile asks for nothing beyond the download.
FastR holds the better App Store score, 4.4 against 3.8. Both are backed by a comparable volume of ratings — 239 and 290 respectively. Written reviews complicate that: 52% of JB4 Mobile's written reviews are positive against 38% of FastR'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, FastR every 5 months. The most recent releases landed on September 23, 2026 and September 18, 2026 respectively.
| Parameter | JB4 Mobile | FastR |
|---|---|---|
| Price | $27.99 | Free — better |
| Rating | 3.8 (239 ratings) | 4.4 (290 ratings) — better |
| Positive reviews | 52.4% of reviews — better | 37.5% of reviews |
| Number of ratings | 239 | 290 — better |
| Update frequency | Every 3 months — better | Every 5 months |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Best chart rank | #2 — better | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 15.1 | 15.0 — better |
| Further details — not scored | ||
| Size | 24 MB | 20 MB |
| Age rating | 4+ | 4+ |
| Developer | Dmac Mobile Developments, LLC | Erhies Fekarurhobo |
Customer experience
JB4 Mobile
FastR
User reviews
JB4 Mobile
From 239 App Store ratingsWhat we love
- 🚀 Great app and a must have with the JB4
- 🔒 Robust security features
- 👍 Awesome data logging
- 👍 Incredible Support
- 👍 Works as expected
Room to improve
- 🐛 Doesn't work properly, screen upside down and backwards
- 🐛 Stopped working after update
- 🐛 Bluetooth connection issues
- 🐛 Gauges freezing
- 🐛 Screen turns off
FastR
From 290 App Store ratingsWhat we love
- 👍 Easy to use interface and simple design
- 💡 Innovative concept for testing 0-60 times without expensive equipment
- 🏆 Competitive leaderboard feature for sharing times
- 📱 Well-designed app layout
- ✅ Accurate readings for slower vehicles (6+ second 0-60 times)
Room to improve
- 🐛 Severe GPS lag and timing delays (1-3+ seconds behind actual speed)
- ❌ Highly inaccurate for high-performance vehicles (sub-5 second 0-60)
- 🔌 Network connection issues preventing app functionality
- 📵 Login and authentication problems (Facebook-only requirement)
- ⚠️ Inconsistent and unreliable acceleration measurements
Bugs and requests
JB4 Mobile
Reported bugs
5 issues- App crashes
- Can't connect to server
- Mirrored/inverted display
- Compatibility issues with new iOS versions
- Trouble logging in
Requested features
5 requests- Add CarPlay support
- Allow customizing map names
- Add more gauge styling options
- Improve UI and layout
- Integrate with Apple Carplay
FastR
Reported bugs
10 issues- Network connection errors preventing vehicle selection
- Facebook login buffering and not connecting
- App fails to record and save acceleration times
- GPS speed readings lag significantly behind actual speed
- App crashes on launch or during use
Show 5 moreShow fewer
- Settings not saving properly without login
- Leaderboard functionality broken
- App doesn't start recording until vehicle is already at speed
- Inconsistent timing results on identical driving conditions
- Loading screen stuck on 'select vehicle' with persistent network errors
Requested features
10 requests- GPS-based auto-start feature instead of manual start button
- Audio cues for 'ready, set, go' countdown
- Alternative login methods beyond Facebook
- Save vehicle selection for future sessions
- Support for multiple vehicles per account
Show 5 moreShow fewer
- Social media sharing integration
- In-app instructions and user guide
- Add missing car models (Tesla Model Y, Russian models, high-spec variants)
- Allow custom vehicle entry if model not found
- Real-time sound feedback during acceleration test
In-app purchases
JB4 Mobile
No in-app purchases
FastR
- 10 Leaderboard Posts$3.99
- Unlock 1/4 Mile Timing$5.99
