Therapy box | Native Mobile application development | Crysberry

Therapy box

Native iOS SDK that enables to browse content using head- or eye-tracking.


Project overview

Native iOS SDK that enables to browse content using head- or eye-tracking.

The new version of the client’s Predictable application — a service that helps people with traumas or diseases to speak. One of the parts of the application is AR-based tracking for those people who lost their ability to move partially or completely. Thus, they will be able to use the application using only head or eye movements.

Our native iOS SDK can be integrated into any iOS- or ReactNative application. To date, the SDK is capable of performing head- and eye-tracking to draw a virtual cursor in order to navigate through the application. The SDK also includes an exhaustive Wiki documentation that describes how to interact with it in full.

ar application develop


Therapy box




Staff Augmentation


1 iOS, i PM


  • Swift;
  • UIKit;
  • ARKit.


The client needed to add new features to the application — eye- and head-tracking.

The most challenging part was to make eye-tracking reliable. The current cameras and hardware are simply not capable of precise processing of such small things like human eyeballs from the distance of 30-40 centimeters.

We managed to achieve a decent accuracy so that users are able to interact with elements of size at least 100 x 100 points on the iPhone screen.

Key Features

  • Universal SDK that can be built into any application;
  • Head-tracking with lots of adjustments (sensitivity, basic head position, etc.);
  • Reliable eye-tracking;
  • 8 different trigger options (hover, blink, smile, etc.);
  • Triggers calibration;
  • The demo application that represents the whole functionality;
  • Wiki documentation.
ar application