Need help in running app in background

[FitDudeMan]

How do you make app run in background even when you turn off display or close the app? Is it even possible? 

[Gondwana]

There is no 'background'. When the display goes off, your app is still running. When another app starts running, your app is closed.

[FitDudeMan]

Thanks, but what are the timers and alarms clock. How do they work on the fitbit watch? You can start a timer or alarm and close app(also turn off displays) and it still runs. I was working on implementing a timer app. Thanks. 

[Gondwana]

I think they use operating system features that aren't available to us.

[FitDudeMan]

Ok thanks. I have one more question. Can you run the companion app without the watch app? I was wondering if it possible to open an app on the watch from the smart phone. Thanks.

[Gondwana]

Sorry, no. An app's companion can only run when the corresponding watch clockface/app is running.

Your second idea would mean that one app could forcibly close another one (since only one can be running at a time).