Google just announced Android Open Accessory, which will allow developers to create accessories that take advantage of software installed on Android devices. Google will offer hardware and software support for the open accessory design kit (ADK) there’s no approval process or fees. In one demo, a Google employee showed off a device with a USB accessory called CardioQuest for monitoring his heartbeat while exercising. In another, a user controlled the classic labyrinth board game using his tablet. In yet another demo, Google demoed the power of its ADK with a life-sized labyrinth controlled by a tablet. Android Open Accessory allows accessory makers to create apps that take advantage of the accessory — if an owner plugs a device into their phone, the user will be prompted to install the corresponding software. It’s available for Honeycomb and Gingerbread devices and works with USB now but Bluetooth support is coming in the future.