Hi, It must be pretty straight forward doing this as you would be with other controls. If you have boolean property in your case map it to checkbox control and in the action choose what you want to do with it when selected and not selected in an activity. If you want to run activity immediately as you select, you must "Post value" but if you are going to run as part of your "Submit" action you don't need to post.
In the above sample activity exits when checkbox is not selected. But there could be another step if there need to be different action when not selected.