When you raise your arm, WorkerSafety Pro is always there. Learn how to change that setting here.As nice as it is to see the WorkerSafety Pro app, sometimes we just want to see our beautiful watch faces. Here is an article written by Apple which details how to have apps like WorkerSafety Pro which use a session to monitor for falls, run in the background without always appearing when you raise your wrist. This should allow the app to run as you would like.
You can read the article here. Look under the section "Return to the clock face".