lightweight page which can beep at specified intervals, good for interval training for running.
load in a mobile browser at https://andywolff.github.io/intervalrunner/?intervals=1,2,2,1 then hit start and begin walking. When you hear three ascending beeps, start running. When you hear a single long low beep, go back to walking. Repeat until done. You can pause by hitting stop, then resume by hitting start again.
Adjust intervals by entering different values for the intervals
URL param. Values are in minutes and support decimals.