Kontakt.io is a beacon hardware and software platform. The Kontakt.io API allows developers to get information on and update their beacon devices. Beacons are small Bluetooth radio transmitters that broadcast a signal at regular intervals. Bluetooth-equipped devices, like smartphones, can detect beacons once they're in range. The combination of the Kontakt.io API and the Kontakt.io beacons allow developers to create proximity-based solutions.