Revolutionary indoor navigation for iOS


Clew is a path retracing app designed for blind and visually impaired users to help them independently return to any desired locations.

Using Apple's new ARKit built for iOS 11 devices, Clew records a path and guides the user back to their starting location with a choice of voice directions, sound effects, and haptic feedback. Download the Clew app today. We welcome your feedback to improve the Clew experience.

A closeup of a hand holding a phone running Clew.  The image on the phone shows a row of seats, as in a movie theater.  The text on the screen says "continue straight for 4 feet"


an animation of the process by which the Clew app builds a map.  The animation shows the creation of navigation waypoints from the raw motion data.


Augmented reality, exemplified by Apple's ARKit, superimposes virtual elements onto the real world. In this case, we add virtual "keypoints" to navigate you through unknown areas.

What it does

  • As you walk to a location, your phone keeps track of its path with a series of virtual crumbs.
  • After you get there, your phone simplifies the path to a series of "keypoints" where you made a turn or used a stairway.
  • As you navigate back, your phone will give you instructions to each point, in reverse order, until you reach your starting location again.
  • You're now back at your seat, classroom, or restaurant table. Enjoy yourself

Frequently Asked Questions

What is Clew?

Clew is an indoor, path tracing navigation app built for blind and visually impaired users. It is designed to remember a location like a seat or a room and assist you to return to that destination after exploring your surrounding environment.

How can I get Clew?

Clew is available for free on the App Store and is compatible with iPhone 6s and newer models running iOS11. For the full haptic experience, iPhone 7 and newer is recommended.

What’s the best way to use Clew?

To ensure that the camera is fully capturing your surroundings, hold the phone in a vertical portrait position with the camera facing away from you while you use Clew. Also, make sure the camera is fairly stable to ensure accurate location tracking.

In what environment does Clew work best?

Clew works best in well lit areas with distinct visual features and few moving objects like crowds and cars. Although Clew can be used outdoors, it is not as accurate in open areas and intense sunlight. Clew works optimally indoors over relatively short distances.

What is the pause feature?

You can pause Clew once you arrive at your destination and before you start navigating back. Press the pause button on the bottom right corner and follow the instructions. Once Clew is paused, you can exit the app to do other tasks or lock the phone as long as you don’t shut down Clew from the app switcher. When you are ready to return, press the resume button and follow the instructions to start tracking.

How can I report a problem?

Please use Clew at your own discretion. Clew's ability to track your movement through a space can be affected by many factors (lighting conditions, the orientation at which you hold your phone, etc.), and therefore may not function correctly all the time. Help us improve the system by rating your routes as good or bad. Bad routes will examined to further refine the app. If you'd like to offer additional feedback, the easiest way to do so is to e-mail the Clew team.


Clew will log the 3D path that your phone travelled when using the app. We use this 3D path information to understand the app's shortcomings and to improve its accuracy. We do not tie this 3D path information to the location where the path was travelled (e.g., it is not linked to GPS position). We will not share these data logs with any third party; however, we may make aggregate analysis of this data public (e.g., in an academic paper).

Any changes to this privacy policy will be detailed in the app store release notes of future versions of Clew.


Tell us about your Clew experience by sending the Clew team an e-mail.