"View-only" simply means your collaborators may only view your class, without the ability to edit, add, or remove any items in the class (e.g. assignments).
To check if you have view-only or editing privileges within a class, visit your settings by clicking your avatar at the top-right. Scroll down and you will be able to see which classes you can edit and which classes you have "view-only" access to.
Currently, Kiddom's collaboration features are only available as "view-only." Editing access coming soon!
To learn more, watch this tutorial.