Harry's Dyno vs R
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Harry's Dyno
Measure vehicle performance with high precision using GPS and OBD sensors. Test acceleration and deceleration across custom speed ranges, analyze detailed results, and store data locally. Supports external sensors for enhanced accuracy.
- GPS and OBD sensor integration
- Custom speed range testing (acceleration/deceleration)
- Detailed results analysis
- Two-cursor data inspection
- Local data storage and filtering
- Data export to various formats
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Harry's Dyno is a high precision performance measuring app. It utilizes GPS and OBD sensor input to recognize arbitrary speed ranges like 0-60 mph or 100-200 km/h. Both acceleration and deceleration testing is supported. Results can be compared and analyzed in details. Using two-cursor mode, one can inspect subranges of data recorded (e.g. 80 to 120 km/h for a 0 to 200 km/h). Data is stored locally and can be filtered by speed range and vehicle used. It can be exported to various data formats too. Provided the smartphone is mounted in a position with good GPS accuracy, the internal GPS can be used for measurements. For short speed ranges, high powered vehicles, and highest precision, either external GPS or OBD sensors can be connected. OBD adapters are actually preferable as speed changes are available instantly. We have an always up to date list of compatible accessories available here: www.gps-laptimer.de/compatibility/ios For distance based performance testing (quarter mile etc), please use Harry's LapTimer currently. This mode will be added to Harry's Dyno as a free upgrade shortly. For Harry's LapTimer users! Harry's LapTimer GrandPrix has received a free feature upgrade and includes Harry's Dyno functionality now: please follow LapTimer ‣ Race ‣ Performance to use the dyno mode. In case you have used Harry's LapTimer Petrolhead so far, you may either upgrade it to GrandPrix (LapTimer ‣ Administration ‣ Add-ons), or go for Harry's Dyno as a separate app. Enjoy and let us know what you think! For questions, tipps & tricks, and support, please use our forum www.gps-laptimer-forum.de
R
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R-EX is the next-generation high-performance timing application for performance cars. By connecting the high-quality, space-technology GPS device, R-EX, to the application via Bluetooth, you can measure 0-100km/h, 100-200km/h, and similar acceleration times. You can even engage in real-time, live timing sessions with your friends. With the R-EX device, capable of 25 measurements per second (25 Hz), you will achieve more precise timing results.
Screenshots
Verdict
The clearest difference is price: R at Free against Harry's Dyno's $3.99. R also leads on update cadence (fortnightly vs every 3 months). Harry's Dyno's advantage is ads (none vs shown) and iOS requirement (12.0 vs 14.0). On 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
R is free to download; Harry's Dyno costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Harry's Dyno ships an update every 3 months, R fortnightly. The most recent releases landed on September 18, 2026 and July 17, 2026 respectively.
| Parameter | Harry's Dyno | R |
|---|---|---|
| Price | $3.99 | Free — better |
| Rating | 1.0 (2 ratings) — better | — |
| Positive reviews | 0.0% of reviews | — |
| Number of ratings | 2 — better | — |
| Update frequency | Every 3 months | Fortnightly — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 12.0 — better | 14.0 |
| Further details — not scored | ||
| Size | 41 MB | 154 MB |
| Age rating | 4+ | 12+ |
| Developer | Harald Schlangmann | R-EX MOTORSPORTS LTD |
In-app purchases
Harry's Dyno
No in-app purchases
R
No in-app purchases
