ROUSH Lap Timer vs JB4 PRO
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
ROUSH Lap Timer
Record and analyze your vehicle's performance on the track. This app generates in-car video with data overlays and allows for detailed performance analysis to help improve your driving.
- Record vehicle performance
- Analyze track data
- Generate in-car video with data overlays
- Measure performance impact
- Integrate with Health Kit data
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The ROUSH LapTimer application, co-developed with the creator of Harry's LapTimer, let’s you push your vehicle to the limit while recording everything for later playback and evaluation. This high-precision tool will improve your driving ability by letting you see where you can go faster on any track. ROUSH’s LapTimer generates beautiful in-car video recordings with an overlay of vehicle data, ready to be presented on YouTube or other social media sites. Even without video, recorded data from your track day can be analyzed using pre-set views, making it easy to analyze and improve your driving performance. In case heart rates were recorded using Heath Kit, this data can be overlaid to recordings too. Using the ROUSH lap timer, you can change vehicle settings and accurately measure performance impact on your track times.
JB4 PRO
Integrate your performance tuner with your smartphone to adjust engine maps, view real-time data, and manage system settings. This app requires a specific Bluetooth adapter for full functionality.
- Change maps
- Monitor live engine data
- Record logs
- Manage fault codes
- Update JB4 firmware
- Smartphone integration
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Smart phone integration for your JB4 performance tuner to change maps, monitor live engine data, record logs, manage fault codes, update JB4 firmware, and much more! Note the JB4 PRO free app requires the JB4 PRO BT adapter and is not compatible with the JB4 Mobile BT adapter.
Screenshots
Verdict
The clearest difference is review sentiment: JB4 PRO at 50% against ROUSH Lap Timer's 0%. JB4 PRO also leads on price (Free vs $27.99) and rating (4.4 vs 1.0). ROUSH Lap Timer's advantage is iOS requirement (12.0 vs 16.0). On ads, in-app purchases 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
JB4 PRO is free to download; ROUSH Lap Timer costs $27.99 up front. Neither carries in-app purchases, so what you see is what you pay.
JB4 PRO holds the better App Store score, 4.4 against 1.0. That said, the two scores are not equally well evidenced: JB4 PRO has 14 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 0% of ROUSH Lap Timer's written reviews are positive against 50% of JB4 PRO's.
ROUSH Lap Timer ships an update every 3 months, JB4 PRO fortnightly. The most recent releases landed on September 18, 2026 and October 1, 2026 respectively.
| Parameter | ROUSH Lap Timer | JB4 PRO |
|---|---|---|
| Price | $27.99 | Free — better |
| Rating | 1.0 (1 ratings) | 4.4 (14 ratings) — better |
| Positive reviews | 0.0% of reviews | 50.0% of reviews — better |
| Number of ratings | 1 | 14 — better |
| Update frequency | Every 3 months | Fortnightly — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 12.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 71 MB | 22 MB |
| Age rating | 4+ | 4+ |
| Developer | Harald Schlangmann | Burger Motorsports, Inc |
Customer experience
ROUSH Lap Timer
JB4 PRO
In-app purchases
ROUSH Lap Timer
No in-app purchases
JB4 PRO
No in-app purchases
