His innovation, dubbed “Le Chal” ("take me along" in Hindi) pairs a smartphone app with a small actuator sewn inside the sole of one shoe via Bluetooth. The user tells the phone his desired destination, which is translated into electronic commands using voice-recognition software. The app, which can be programmed to run in the background, fetches the local map of the area. The phone’s Global Positioning System (GPS) tracks the person’s location in real-time, telling the actuator to vibrate when it is time to turn. The side of the shoe where the vibration is felt indicates which way to go. Mr Sharma opted for a vibrating signal because for the blind, who rely on their sense of hearing to make sense of the environment, audio feedback is a distraction.
via economist.com