LapTimer is enhanced continuously. Harry's LapTimer Rookie, Petrolhead, and Grand Prix editions are available. Any version can be upgraded using Apple‘s In App Purchase (see Products page).

Our ambition is to provide you with the best GPS tool available on smartphones. LapTimer on iPhone is based on the robust GPS Engine known for years on the PalmOS versions. This GPS Engine was enhanced to fully integrate with the iPhone's acceleration sensors. The front end of LapTimer on iPhone is completely new development featuring a perfect, and beautiful iPhone look & feel. LapTimer uses both the internal GPS or external accessories providing GPS by NMEA. The later option allows much improved accuracy (see GPS page) and reliable receiving conditions. Please check the Compatibility page for supported external GPS and OBD devices.


  1. Automatically starts and stops lap and sector timing using triggers

  2. ‘No Touch’ operation on track

  3. Realizes accuracy better than 0.1s even with standard sensors

  4. Uses custom defined or preloaded triggers

  5. Includes a manual stop watch

Fully Automated GPS-based Lap Timing Tool

  1. Stores all sensor data in its database for later analysis

  2. Offers a broad spectrum of export formats including Google Earth™

  3. Visually shows line driven and lateral acceleration

  4. Analyses braking and acceleration points

  5. Analyses corner and straight speeds

  6. Lap to lap comparison to analyze impact of line driven P

  7. Histogram view on speed, lineal+lateral acceleration, and height

  8. Enhanced Analytics incl. video frame display GP

Powerful Data Recording Tool

  1. Records FullHD, HD, and SD videos DP

  2. Automatically starts and cuts videos to lap length

  3. Allows dashboard overlaying of speed, G-forces, time lapped, OBD DP

  4. Exports data for external overlaying products

  5. Fully integrates with the iPhones asset library, and iCloud

  6. Picture in Picture overlays

  7. Coordinated Multi Cam recording GP

  8. Experimental support for GoPro's HERO3 GP

Video Processor

  1. Driver positions broadcasted to server for online viewing P

  2. Shows times lapped by track as a Hall of Fame

  3. Allows drivers to issue a yellow flag to fellow drivers on same track

  4. Can join data recorded on several devices in one database

Online Enabled

  1. Supports a large variety of internal and external sensors

  2. Dynamically connects / disconnects sensors

  3. Support includes GPS, G-forces, magnetic compass

  4. Support for external sensors (plugged in, WiFi, or Bluetooth)

  5. Native high accuracy access to external GPS sensors

  6. OBD II integration

  7. Calibrates and synchronizes all sources

  8. Supports high update rate sensors (up to 20 Hz) to improve accuracy GP

Sensor Wizard

  1. To date, the online database has more than 450 predefined tracks

  2. Track shapes and descriptions by geography

  3. Certification allows distribution with high quality

  4. Add your custom track definitions and share them with your friends

Prepared for YOUR Track

  1. Internationalized units (length, speeds, power, ...), English, German, French localization

  2. Offers a variety of skins and display setting

  3. Huge number of specialized views to meet driver’s requirements P

  4. Allows customization of nearly everything

  5. Absolutely smooth and intuitive user interface

  6. Database with laps, tracks, vehicles (cars, motorbikes, karts), driver

Incredible Feature Rich

D = Depends on devices    GP = LapTimer Grand Prix    P = LapTimer Petrolhead

D = Depends on devices    GP = LapTimer Grand Prix    P = LapTimer Petrolhead

Copyright © 2006-2013, Harald Schlangmann. All rights reserved. Last revised: 4th Mar 2013

'Doing some data recording' seems to be a simple task in the beginning. Most users diving into the world of LapTimer come with an experience from 'all in one solutions' - these small gray boxes with very limited functionality. Although these solutions are designed on purpose, they need to be limited as they miss the rapid innovation, connectivity, and versatility current smartphones show.

Compared to this all in one solutions, your iPhone is a really high-powered computer! Combine it with Harry’s Lap Timer software and you can quickly and cheaply get your hands on the world-class & incredibly feature-rich GPS lap timer. This can be extended in many ways to give you the best possible information and feedback about your on-track performance.

This page gives you an overview on the feature groups. For more details visit LapTimer Documentation and our Harry's GPS Suite Forum.

Feature Groups