This easy to use tool offers a streamlined way to communicate to many TrainingSpaces at once and to bulk invite new members. Here's how to create a List:

Navigate to Lists and tap "Create a List" or the "+" icon in the top bar.

Name your List then tap "Create" in the top bar and your List is created. Click Edit spaces to select from a list of Spaces to add to the List.

To post media to all the Spaces in the List, tap "Post to List" or the orange capture button. To invite members into all the Spaces, tap the person icon in the top bar and select members there.