I kept ruining good tea with wrong water temperature and steeping time, so I built a free timer that does the remembering for me. Pick your tea (green, white, yellow, oolong, black, pu-erh) and mug or gongfu brewing, and it shows the water temperature, how much leaf to use, and counts down each steep — with a beep when it's ready. Mild / medium / strong, ±30s adjust, keeps running if you switch tabs. English and Chinese in one click. Free, no account.
