You control who can view, run, and edit your application in the "App Settings" section of the application editor. Under "App Settings" you have three separate menu points: "Owner", "Visibility", and an open-source option.
Owner: The "Owner" of a BioLib application, in effect, is the admin user. When editing an application one can transfer an application from your personal account to a team you are a member of.
Visibility: The visibility option sets who can view and run an application. There are three different visibility modes:
Open-source: If the option is set to "Yes", anyone with permission to view and run the application will be able to also download all the source files including executables.