The Other Half (TOH) is a swappable back cover that does more than protect your phone — it transforms it. The original Jolla Phone (2013) pioneered this with open I2C interface and NFC-enabled covers that changed themes and behaviour just by snapping on

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With the new Jolla Phone, we’re taking TOH even further — and we’ll open source the hardware and software interface specs so anyone can design, 3D-print, or produce their own modules. Primarily we plan that the new The Other Half interface would be based on I³C.