Countdown timer in sample app

[Kirk_Masden]

I've made a sample / template app that shows how one can use a gif to implement a simple 30-second countdown timer:

https://www.appsheet.com/templates?appGuidString=bd3c764b-8515-44a6-bcd5-d757c7729802

I've used gifs in my apps before but this time I did something different.  Instead of following the precedure I've described here . . .

https://www.googlecloudcommunity.com/gc/Tips-Tricks/Demonstrate-how-to-use-your-app-with-gifs/m-p/39...

. . . I put the gif I made directly on my server and the accessed it via an img src=tag in a virtual column of the LongText type.  This has two advantages:

1. The placement inside HTML in a LongText column makes it possible to make the gif quite small.  In an image column (which was the only choice before we were give access to HTML), it would be pretty big.  Now the countdown clock looks like this:

2. The second advantage is that with the "normal" gif address (before HTML became accessible, only a special way of accessing gifs on Google Drive would work), I can append text as follows:

The text I have appended following a question mark is a version of the time (18:32:34) and I've set up the app to add different text based on the time every time the gif is to be accessed. This causes AppSheet to treat the URL as a completely new one, which means that it always starts at 30 seconds and then begins counting down.

So, that's where I am now.  Here's my question.  When the 30 seconds run out, can I make things happen on the detail view?  For example, can I make a message say "Time's up!"?  Or, can I make the question box  disappear?  I'm not used to working with bots so instead of wasting a lot of time trying to figure it out, I thought I'd just ask.

I would be honored if those of you who happen to be interested in this question would copy my sample and try to tweak it.

Thanks!

P.S. I plan to repost this later as a tip, but I wanted to see if it's possible to improve the implementation a bit before I do so.