Fitness tracking for the Apple Watch

With version 1.3, Tacho comes to the Apple Watch. The new Tacho for Apple Watch app allows you to track your bike rides and save them in the Apple Health app on your iPhone. While tracking, the Tacho for iPhone app now shows your heart rate.
You can also use the watch app entirely without an iPhone. However, the battery of the Apple Watch lasts longer when your iPhone is in range. In this case the GPS sensor of the iPhone is used.

Sophisticated autopause

The autopause function is optimized for cycling. If, for example, at a traffic light stop the GPS signal jumps back and forth a bit, although you are not moving, these artifacts are discarded. Only when you are really moving again and have covered a certain distance, the time and distance are counted retroactively. The app indicates this pending state by a blinking time. This way, no second is counted too much or too little.

Weather powered by Dark Sky

In the previous versions of the app, the weather data came from OpenWeather. With the current version, the weather data is now powered by Dark Sky. The weather info from Dark Sky is more accurate. Especially the air pressure, which is used for the initial calibration of the barometric altimeter, has a much higher resolution and accuracy.

Improved barometric altimeter

Another highlight is the improved barometric altimeter. In the previous version, the altitude was calculated based on the readings of the integrated barometer and the air pressure and temperature from the weather provider. On the one hand, this type of calculation required an internet connection to load the weather data. On the other hand, the accuracy of the altitude was dependent on the accuracy of this weather data.

With the new Tacho version, the barometric altimeter is additionally calibrated using the altitude data from the GPS signal. It automatically calibrates itself as you move. The combination of GPS, integrated barometer and external weather data allows highly accurate altitude tracking.

Download Tacho on the App Store and let me know how you like the update.

Tacho 1.1

Tacho 1.1 is now available on the App Store.

Release notes

  • add barometric alti- and inclinometer
  • add split view support for iPad
  • improve compass accuracy while driving
  • improve weather loading for more accuracy and better energy efficiency
  • adapt to new location permission handling in iOS 13
  • fix compass showing wrong heading when iPad hold upside-down

Let me know how you like it and merry christmas!

Public Beta

I am working on the next Tacho release with these new feature:

  • Barometric altimeter and decline1
  • Split view support for iPad
  • Improved compass accuracy while moving
  • Improved weather loading for higher accuracy and better energy efficency

Join TestFlight and try out the upcoming features now.


1Requires iPhone 6, iPhone 6s, iPhone 7, iPhone 8, iPhone X, iPhone XS, iPhone XR, iPhone 11, iPhone 11 Pro, iPad Air 2, iPad mini 3, iPad Pro or iPad (5. Generation).

Hello Tacho

Hello, I am Friedemann. I ❤️ 📷, 🚲 & <code/>. And I am the developer of Tacho.

The Prototyp

In the summer of 2013 I bought a new bike, a Brompton in Raw Laquer with 2-speed gear and Schwalbe Kojak slicks.

Of course, I needed a speedometer for my new racing Brompton. Since nothing could convince me in the App Store, I made my own bicycle computer. Speed, total distance and time my first iPhone app displayed. I had the app in use for more than five years and more than 7000 kilometers and was quite satisfied. Only a temperature gauge I have occasionally missed.

Tacho 1.0

At the beginning of this year, during the spring cleaning of my bike, it has seized me again. I finally wanted to implement the temperature gauge and had an idea how to visualize wind information.

I was tired of the old Objective-C code. So I developed a completely new app with React Native. But I was not really happy with the result. The compass animation ran with 60 fps, but did not feel buttery soft and the power consumption was too high.

I could not help getting into Swift and porting the app. But the effort was worth it. The animations run buttery soft, need little energy and the bundle size has shrunk from more than 40 MB to 1.5 MB. 🚀

With the new app, I have now gone the last mile and finalized it for the App Store. Since May you can 🎉 download Tacho for free on the App Store 🎉. It is translated to English, German, French, Spanish, Korean and Arabic and available for iPhone and iPad.

I have many ideas for the future, both for the app and for the blog. Tacho 1.1 is already in the works, a beta version is coming soon.

So download Tacho on the App Store, subscribe to the blog, follow me on Twitter, signup for the newsletter and send me your feedback!