Useful for ebooks but would add one thing.
I enjoy using this timer along with Sarah’s ebook (I have the Body & Bump as I’m currently 33+ weeks pregnant.) My only suggestion would be to add a 20 second rest period in the custom timer. For the cardio section it says to do “30 SEC ON 20 SEC OFF) there is not a 20 second option, just a 10 or 30+. I’ve been doing 40 seconds on 10 seconds off. But it’s frustrating to have to watch the timer so closely to make sure I’m resting after the 30 seconds of activity.