[modulusprime]

For Android, there is a very simple free app called ExerTime ( https://play.google.com/store/apps/details?id=com.aisknab.ex... ). It's not pretty and the configuration UI is both annoying and confusing (you must enter the total elapsed time at each step, not the time-per-step), but the normal use case works really well. The right options are available (notification sound, audio channel, text-to-speech, screen lock).