StrokeRateCoach is a rowing app that beeps at a desired rate per minute - in other words, a metronome.
Simple SPM (Strokes Per Minute) rate setting is supported, as well as complex workouts based on distance, time or stroke count.
StrokeRateCoach will happily beep from the background, so feel free to combine it with other sports apps.
This app created by batyanko, enthusiast rower and android developer.
Any questions and feedback welcome, especially bug reports.