Application owners can be assigned by clicking on the admin site > Assets > [Home Site] > Apps > and then locating "assign app owners" on the right hand side. Application Owners have full rights to view, add, edit and delete any content within the application. They have management rights over their application(s) and are able to create categories and assign user and group level permissions. You can assign individuals or whole groups to be app owners.
Security is applied at both the folder, and form levels.
Folder Level Security
Under the Application Toolbox click on "manage folders" and then click into a folder, where you will see folder security is currently set to OFF. Click [apply] to apply security settings to this folder. Using folder level security, users can be given rights over all forms created within that folder. By default, all users have rights to view the forms, and fill them out. Users can also be given rights to edit the forms within that folder, add forms to the folder, or delete the forms within that folder.
Form Level Security
Security can be applied at the form level under the Security tab. The form will remind you what the folder level permissions are for this form and give you the option to override these settings or add to them. There is the option to make all form submissions anonymous, which is a good option for surveys.
You can also apply security to form responses. The Submitting User, the User's Supervisor, or chosen individual users or groups can be given rights to view, edit, or delete the submitting user's responses, as well as the option to view approval if workflow has been added to the form.