RollCall
A classroom name picker that runs from a USB stick: offline, bilingual, and fair by design.
Shared school computers get wiped, and student names are personal data under China's privacy law (PIPL). So the whole app is one HTML file with no network code: plug in the USB, double-click, spin.
The problem:
You need to call on students fairly, but classroom computers are shared, get wiped, and often have no internet.
Constraints:
It has to work offline, keep data only on the USB stick, protect student privacy, and work in English and Chinese.
Design decisions:
Picks use the browser's secure random generator.
"Favor least-picked" never hides its bias, because slice sizes always show each student's real odds.
Data saves straight to a file on the USB and reconnects by itself next time.
It reads the SchoolPal class export (.xlsx) directly.
The controls sit at the bottom of the screen for touch screens.