Comparison

GPS Race Timer vs RENNtech HSM

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

GPS Race Timer

Accurately measure vehicle acceleration times like 0-60 mph and 1/4 mile using your iPhone's GPS. Set up timers beforehand and let the app automatically start measurements when speed targets are met or motion is detected. Save, export, and transfer your performance data easily.

Highlights
  • Measure 0-60 mph, 60-120 mph, 1/4 mile
  • Automatic start detection
  • Save and export results
  • Preset and adjustable timers
  • No extra hardware required
  • Optional PRO version features
Read full description

Measure acceleration times such as 0–60 mph, 60–120 mph and 1/4 mile directly with your iPhone — accurately and without extra hardware. The app is designed so it doesn’t need to be operated while driving; you just set everything up beforehand while stationary. Measurements then start automatically — when the target speed is reached or when a start is detected. You can save results locally on your iPhone and, if needed, export them or transfer them to other devices. Preset timers: 60 ft, 1/8 mile, 1/4 mile, 1/2 mile, 1 mile, 0 – 60 mph, 0 – 120 mph, 50 – 75 mph, 60 – 120 mph, 0 – 100 km/h, 0 – 200 km/h, 80 – 120 km/h, 100 – 200 km/h. All timers are, of course, fully adjustable. The free version measures up to two times per run. How to use the app: Check the timer settings on the start screen. If everything looks good, place your iPhone in the car where it has good GPS reception and is held securely, then start the acceleration test. You can adjust the timer configuration in the Settings screen (just tap the relevant timer). Then return to the race screen and follow the previous instruction. Optional PRO version (in-app purchase): 1. Up to four timers in parallel (instead of two) 2. Precise determination of elevation differences 3. Simulation of a Sportsman start and reaction-time measurement 4. No ad banners

About

RENNtech HSM

Read full description

An application used to control the Bluetooth version of the RENNtech Hand-held Suspension Module (HSM-BLE - RENNtech PN 32.971.8001). This application will allow you to change the ride-height of your Airmatic or ABC Suspension Mercedes using the RENNtech HSM-BLE device. Save up to three different profiles for quick access to your favorite ride-height settings. Please note that this application is not compatible with RENNtech HSM PN 32.222.6001.

Screenshots

GPS Race Timer4 screens
RENNtech HSM1 screens

Verdict

The call

The clearest difference is in-app purchases: RENNtech HSM at none against GPS Race Timer's 1. RENNtech HSM also leads on ads (none vs shown) and update cadence (every 3 months vs every 7 months). GPS Race Timer's advantage is iOS requirement (12.2 vs 16.0). On price 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. GPS Race Timer sells 1 one-off in-app purchase. RENNtech HSM asks for nothing beyond the download.

UpkeepUpdate frequency

GPS Race Timer ships an update every 7 months, RENNtech HSM every 3 months. Both last shipped on October 25, 2026.

Scorecard4 real differences · 6 level
GPS Race Timer versus RENNtech HSM: the parameters behind the verdict, then further details
ParameterGPS Race TimerRENNtech HSM
PriceFreeFree
Rating4.5 (2.8K ratings) — better—
Positive reviews34.4% of reviews—
Number of ratings2.8K — better—
Update frequencyEvery 7 monthsEvery 3 months — better
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.2 — better16.0
Further details — not scored
Size50 MB4 MB
Age rating4+4+
DeveloperThomas HagenauDian Esterhuyse

Bugs and requests

GPS Race Timer

Reported bugs

4 issues
  • Timer doesn't reset properly
  • App crashes on startup
  • Significant GPS/speed detection delays
  • Recorded times do not match actual performance

Requested features

4 requests
  • Add 60ft and 1/8 mile times
  • Automatic start/stop of timer
  • Manual start option for timer
  • Improved accuracy and consistency

RENNtech HSM

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

GPS Race Timer

One-time1
  • PRO$4.99
None

RENNtech HSM

No in-app purchases

Questions

Is GPS Race Timer free?
GPS Race Timer is free to download, with in-app purchases available.
Is RENNtech HSM free?
RENNtech HSM is free to download, with no in-app purchases.
Do GPS Race Timer or RENNtech HSM have ads?
GPS Race Timer shows ads; RENNtech HSM does not.
Which is updated more often, GPS Race Timer or RENNtech HSM?
GPS Race Timer ships an update every 7 months, and RENNtech HSM every 3 months. Most recently, GPS Race Timer was updated on October 25, 2026 and RENNtech HSM on October 25, 2026.

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