TOH interface is the highlight of the spec. i2c is slow but it is cheap to implement on TOH and the protocol is dead simple but flexible. Anyone expect a add-on camera/CPU/RAM need to wake up and understand it is too costly extending the hardware this way. But for adding xenon flash, hkb, sensors and input devices, i2c is sufficient. But will Jolla give developer full access to TOH or only provide a high-level API?