The easiest way to use Prettifier is to use the existing GitHub Application. It is free for public and private repositories.
All repositoriesor choose the repositories to add Prettifier to
Prettifier is an application under ongoing development. It might ask you for new permissions once in a while. Please accept them, otherwise Prettifier might cease to function properly. If you have questions or concerns about permissions, see what Prettifier does with them in the source code or open an issue.