Point the camera at a sunflower disk so it fills the ring. The first words come from far; the rest as you come closer. No server: everything happens on this phone.
of 1024 seeds · long-press the disk to save it, then print it or show it on another screen
Fib in: Fibonacci coding + 2 check bytes. Poincaré: each bit a grating at a sunflower seed in the frequency plane, low frequencies first. Fib out: the FFT is the detector; three pilots give rotation and scale. Works at any rotation; the disk should fill 70–100 % of the ring; strong tilt is not corrected.