What is Traces?

Traces is an app that records GPS coordinates and overlays them on a single map. This enables people to know, where they have been and where not.

In a broader sense, Traces is also a software suite, which currently contains three software:

  1. Traces iOS: records and visualizes traces (a GPS track is called trace) on iOS devices
  2. Traces Web: visualizes and manages traces
  3. Traces Recorder iOS: records traces


The idea of Traces can be traced back in the summer of 2014. At that time, I was studying in a French city Rouen, Normandy. I was truly attracted by the layout of the city and the aesthetics of the buildings. I wanted to see it all. I ran, biked and even took local buses to discovery different neighborhoods. But as I visited more streets, I have a problem remembering them. There were many deja-vu moments. How can I solve the problem? Can I overlay all my GPX files in a single map? With some research, I achieved that with Mapbox.


Early web version based on Mapbox in Nov 2014.

Looks good huh?

In early 2015, I moved to Palaiseau to start my internship in Peugeot. Palaiseau is around 25 KM from Paris center. On weekends, I would usually take the RER train to the city. The city as everyone knows it, enjoys many tags, romantic, historic, art, monument, you name it. Fascinated, I wanted to explore the capital de la France!

Soon the web version become unresponsive often. That was the time I wanted to take a leap and start off an iOS app that handles better with performance. Within one or two months, Traces was created and released on the App Store. It was built with Swift 1.2, a very early release of Swift.

What is Traces Recorder?

Sometimes it is wanted to have a dedicated GPS recorder, for several reasons:

  • smallest memory footprint: no traces visualization and management.
  • powerful recording feature: free from the UI limitation from Traces app, possible to create a real time speed chart, follow a planned trajectory, etc.
  • different map: no trace visualization means less dependency on map SDK, possible to have different map support.

Traces Recorder is created for these reasons. Saved GPX files are still in the iCloud Drive, same folder as Traces, which can import the files without a hassle. It can be used standalone. But it is best served along with Traces.