OK, be mindful that glide apps are basically webpages running on top of the browser. Browsers tend to cache things when possible. As for images, they are retrieved BY the app. They are not sent TO the app. If the url remains the same then it’s very likely that the app will retrieve the cached version.
There is a trick to get the image to update if the url remains the same. This is called a cache bust. Essentially you add a dummy query parameter to the image url with a value that changes either based on time or based on a value that is manually updated. What you do is create a template column and set it up like this:
{URL}&cachebust={VALUE}
Replace {URL} with the image column url. Replace {VALUE} with anything you want as long as it changes whenever the image is updated. It could be a timestamp, it could be a calculated math date so it could update every year, month, day, hour, minute, second. It could be a random string of text. It could number that you increment whenever the image is updated. Really anything as long as it changes at the same time that the image is updated. However, I really wouldn’t recommend using a current time based cache bust. If done incorrectly, you would have that image loading unnecessarily up to every 10 seconds, which would not be good. Instead use a value such as an Increment value, or a static timestamp.
With the query parameter in the url, the query parameter will be ignored by the app, but the url will change, causing a new version to re-cache.
Not sure I follow…
This is hard to say and may depend on the device and/or browser. I just tried it in one of my apps. I use dark mode on my android phone. I checked the box and within 10 seconds, the app switched to dark to match my phone theme. I then unchecked the box and within 10 seconds the app reverted back to light mode. So I my experience it works.
I will say this though. I feel that some things can get hard set when an app is installed. That is usually the app icon and splash screen color. To reset that you would need to uninstall the app, clear browser cache and possibly cookies for your app’s url, and then reinstall. This may or may not include the match device theme setting as a hard set value.
For any other type structural update, they usually migrate to all end users eventually within a handful of minutes, but a force close and reopen is usually enough to retrieve updated structural changes.