However.. in the app it's not there and only the text is displayed:
Also, it seems it's not possible to have it initially closed. The container always starts open. Any way to remedy this?
Apologies @BobandBill, this is a new feature that seems to have made it to the website before the app stores accepted the apps that supported it. It will be supported in the app version to be published in the next 24-48 hours.
will it be removed in the mean time? 
I'm already using it?
It will not be removed! That's one contract we keep with builders -- we almost never remove features!
Is it possible to have it closed by default? So not “collapsible” but rather “expandable”?
I use it for a help section. If people want more information, then can expand it. @bca
Unfortunately not yet, but I'll file a request! In the meantime you can hack it together with a Button, Icon or clickable Image and the Hidden property of a regular Container.
Hello there,
I have the same problem, fixed it by using a switch and a container and having the following:
Would be great to have collapsible ready, but that does it for now.
Does it have an animation? I think this approach would work but it will not be animated.
@bca is there any update on this? I never use a collapsible. An expendable is more useful because you would want to hide extra information but want it easily accessible.
Hey @Steven_W! The code to allow the body to be hidden on app load is written and going through the release process. I'll update you here when I have an ETA, but this should be available pretty soon.
@Steven_W @BobandBill @Omar_Tarek I've turned on a Feature Flag for your orgs to show this toggle. Let us know how it looks!
What does that mean? Can we try it already? 
