The smartphone -- an unbranded Android handset -- had undergone one key modification: its front-facing camera had been swapped out for a light sensor. A nondescript tablet, too, had undergone the same procedure, and a cheap, gummy bear-shaped LiFi dongle showed a way to retrofit devices via the headphone jack. After loading up an app on the smartphone, holding it within range of lamplight immediately triggered events like displaying a picture, or playing a video. Images and clips were stored on the phone, of course, but nevertheless, the demo showed the potential of one-way LiFi transmissions in mobile devices. Oledcomm, which provides other companies with LiFi infrastructure and software services, imagines implementations from precise indoor geolocation to in-store advertising. For mainstream adoption of the technology, though, the outfit first hopes smartphone manufacturers will add light sensors to their handsets as standard.