This app was mentioned in 11 comments, with an average of 1.36 upvotes
Just discovered this a few weeks ago. One of the few ones that can do vibrate only or sound through headphones rather than as an alarm
Just a follow up, I have found a timer with the features I was looking for!
Complex Timer
https://play.google.com/store/apps/details?id=com.deslomator.complextimer
I had to broaden my horizon beyond tea timer apps and this is the one. You can set up a sequence of timers per tea and have the next steeping queue up automatically, it's perfect!
I used Impetus Timer, but now I switched to Complex timer. Basically it is the same but with a more appealing interface I think.
https://play.google.com/store/apps/details?id=com.deslomator.complextimer
I like Complex Timer. You can make your own routines pretty easily.
I have the exact app you need, is called Complex Timer.
https://play.google.com/store/apps/details?id=com.deslomator.complextimer
So I found two possible options. Below is something called "Complex Timer" that lets you program your time for your workout. You'll have to manually set the times before the workout, but it can do the X seconds work, X seconds rest function you need.
https://play.google.com/store/apps/details?id=com.deslomator.complextimer&hl=en_US&gl=US
The second possibility would be hourglass apps. You can set some arbitrary time like an hour and let it run, then flip the glass and it'll count back down. It's less sophisticated than the previous timer but it functions exactly like you described. Below is "Sand Timer" that looks like it fits the bill.
https://play.google.com/store/apps/details?id=com.keuwl.sandtimer&hl=en_US&gl=US
Please let me know if this helps.
App - Complex Timer
Custom countdown pattern for workout and sessions
https://play.google.com/store/apps/details?id=com.deslomator.complextimer
I use this app for interval training: https://play.google.com/store/apps/details?id=com.deslomator.complextimer
I use Complex Timer to schedule both rests and holds.
Have a look at Complex Timer. I have not really used it but it seems very flexible.