This app was mentioned in 4 comments, with an average of 1.00 upvote
Technically a boxing/MMA timer app, but this is what I use for this type of stuff.
Linkme: Workout Timer https://play.google.com/store/apps/details?id=com.muhanov
There's also this one:
Linkme: Interval Timer https://play.google.com/store/apps/details?id=cc.dreamspark.intervaltimer
I've been using Round & Workout Timer for years, across multiple Android phones including Galaxys. I used the free one for most of those years but recently paid for it. It allows the creation of multiple "profiles" which is really just your work and rest scheme. You can set intra-round alerts and a delay from when you click start to when the timer starts running.
The only complaint I have about the program is, if you've got it running and set to keep the screen on and for some reason you click over to a different app then click back, that screen lock is lost and your phone will go to sleep on its regular schedule.
Other than that one caveat, it's perfect. I've used other timers and none have been able to consistenly do the job as well as this one.
https://play.google.com/store/apps/details?id=com.muhanov&hl=en
This one isn't anything special but it does exactly what I want and I've been using it for years.