I have to switch between various machines so I use my phone. Then I find any app to be overkill and limiting at the same time. I recommend using a timer and you

I have to switch between various machines so I use my phone. Then I find any app to be overkill and limiting at the same time. I recommend using a timer and your phone's timer will do. Set timers for 25mins, 5 mins and 15mins and go!