Hey creators, I have created a simple app to to keep track of some instruments and I'm trying to add a Countdown timer for each individual item in the Gallery.
Context: Need to start a 3hour countdown for the selected Item only, after a Form is edited and Submit button is clicked. Once the countdown is 0, need a particular data in the selected parent Item to be erased. (Timer needs to be counting down even after closing the app)

This is one of the item in gallery.
Timer functions : 'Text'=Text(Time(0, 0,(Timer7.Duration-Timer7.Value)/1000), "hh:mm:ss") & 'Duration'=10800000
The 'Start' for Timer control is set to a variable 'TimerStart' which is defined in another screen as mentioned below
The 'OnSelect' for Submit button to a form is = SubmitForm(EditForm1);Set(TimerStart, true);
The timer doesn't seem to start after clicking the Submit form and going back to the Gallery(even if it does start, timers are counting down for all the items instead of selected one. Also how do I delete data in the selected item after the timer countsdown to 0 (Realworld usage: remove the username from the instrument after 3 hours)