Harry's LapTimer is the advanced tool for car enthusiast. It records all types of sensor data provided by your iPhone/iPod/iPad (or external sensors), combines them, and makes them available to optimize your drive. Over time, you will get insights on your car and in your driving, not known before.

LapTimer offers more than 1000 predefined tracks world wide. With its assistants, it is extremely easy to setup - just click your track and drive. It fully automates your lap timing using GPS, and presents the results to all kinds of media.

You are not limited to track driving only. For example, you may define your home and working locations as a 'track', collect statistics on different ways chosen, and analyze / optimize the time used every day.

Want to show your drive to your friends? LapTimer generates beautiful in car video recordings with all kinds of data overlaid, ready to be presented - e.g. on youtube. Even without video, recorded data can be analyzed using purpose designed views, making it easy to analyze and improve your driving performance.

Using online racing, you can use LapTimer in competition. LapTimer offers a Hall of Fame, allows watching you and your friends on track - all in real time. Compare your sector times, braking / acceleration points, and learn from each other.

You can start with your plain iPhone in the beginning and add external GPS and OBD II sensors later, step by step, and as you need it. LapTimer itself comes in three different editions: LapTimer Rookie is the entry level with all you need for lap timing; LapTimer Petrolhead is the advanced version including lots of video features, and LapTimer Grand Prix is the edition for professionals including Multi Cam recording, and advanced sensor and analytics functionality.

Please note that functionality depends on your device, the LapTimer edition chosen, and sometimes even external sensors added (like OBD II). Please visit our web page to get the full story. All edition can be upgraded later, all editions come with native iPhone and iPad support.

There are quite expensive stand alone solutions for track days available. Be smart and own the leading edge tool simply by using your iPhone and LapTimer. Besides the professional area, there is no known solution that offers more functionality than LapTimer does - across the market. As our ambition is to offer the best tool, LapTimer is enhanced continuously.

Please visit for detailed information on versions, FAQs / documentation, in depth technology background information, online racing, and supported device configurations. Join our user community on to be involved in future development - all with first class support.

What's New

Version 21.2.0

Changed in v21.2

‣ Added full support for native resolutions (iPhones X, 8, 8 Plus)
‣ Raised minimal iOS version to 9.3
‣ Added tool bar for all list views
‣ Multiple changes to sensor framework, added Expert Settings
‣ Added support for TONWON BTLE OBD sensor
‣ Added a work around for Alfa Romeo Giulia QV OBD replies
‣ Simplified sensor delay scheme
‣ Memory and performance optimizations

We have massive changes to the user interface in this version.
In case you observe misalignments or see something that needs to be trimmed,
please drop us a note!

Ratings and Reviews

3.9 out of 5

7 Ratings

7 Ratings

You'd have to pay at least $1000 to get this performance otherwise.


Harry's lap timer pro is more than just a toy. I am an autocrosser, and use Lap Timer Pro as my primary data acquisition tool. I am using it with an Emprum 5 Hz GPS dongle and a WiFi OBDII reader (generic Chinese PLXII knock-off). The total investment in hardware accessories and software was about $180. The tool does what you'd have to pay over $1000 for otherwise (Traqmate, Race Technologies DL1 etc). It works very well, with lots of features including data export to many formats and video overlays to iphone video and external video source. Service is spectacular (you talk with Harry directly, and he solves problems usually within 1 day). Updates and bug fixes come constantly, along with new features.

That being said, there are a few negatives. Reliability when connecting to the GPS and WIFi unit could be improved. I've found a procedure that works, though. The app is not happy if you get it going, quit or put it in the background and then come back without reconnecting the external devices. I am now in the habit of reconnecting the GPS and wifi every time I start the app, which works well. Also, if you're somewhere hot, the iphone can overheat and go into shutdown. There are some tricks to mitigate this. I live in Phoenix, though, which is as bad as it gets. Even with these issues, Harry's Lap Timer is an astounding value, and a real showpiece for what is possible with iphone apps.

Marginally Useful


I had high hopes for this program and after playing around with in in the car on city streets I was ready to give it a go. Taking the laptimer out onto the track I quickly started to find a flaw not with the software but with the ability to track sate-lights fast enough to be useful. Beyond iphone limitations the software gives very little analysis and exported files are all but useless on a mac which can only utilize the google earth files (again interesting but not helpful). I will continue to use the program for the one feature which seems to work consistently and thats tracking lap times (thats it, just the time of the lap). Everything else is seriously lacking, for example my last lap for the day: purported 63 miles on a 2 mile course, averaged speed of 146 mph with a max speed of 110 and a 5180 ft elevation change (thats about 1 mile vertical over a 2 mile course). The phone was set with an unobstructed view of the sky and mounted on the seat behind the driver and the error seems to be with ghost points or skipped points, perhaps later software developments can overcome the limits of the phone, but I have my doubts. So.. if you need an accurate laptimer this will work, but if you need something more... your going to have to look outside the ap store.

Worst interface ever

Josh Graessley

The most irritating thing is that this seems to be the best app for this sort of thing. The user interface is some sick, cruel joke. The app locks up from time to time. The list of tracks truncated the useful information (Buttonwillow clockwise vs counter clockwise). The settings are impossible to understand.

The problem is, if you can get it set up and working the results are brilliant. The overlay of the track map, accelerometer and speed over video are great. Unfortunately, you can't hit a button to automatically overlay ever lap, you have to manually go through and overlay each one. Adding insult to injury, the overlay settings are reset every time you go in to overlay, so you have to remember every time to reset the lead in and out to zero and disable that stupid count-down thing.

Trying to load maps is an excercise in frustration. First of all, I'm usually near a track when I want to load it, why not show me the nearby tracks? When tracks nearby have variants, the most important part of the track name is the part that differs (for Thunderhill, is this with the bypass or without? For Buttonwillow, is this clockwise or counter clockwise?). The track list shows the names and truncates the interesting bits. Tapping on the track usually results in loading the details page instead of loading the track.


Harald Schlangmann
81.3 MB
Requires iOS 9.3 or later. Compatible with iPhone, iPad, and iPod touch.
English, French, German, Italian, Japanese, Simplified Chinese, Spanish, Traditional Chinese
Age Rating
Rated 4+
© Harald Schlangmann
In-App Purchases
  1. Grand Prix Upgrade $9.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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