There is a Free version and a Pro version of PublishPress Authors. This table has an overview of the different features in each version:

Authors Free #

Authors Pro #

Author profiles for WordPress users
Author profiles for Guest users
Show authors under your content
Show authors in a shortcode
Show authors in a widget
Choose avatars for each author
Support for custom post types
Basic fields (Name, Email, Bio)
Author pages
Custom fields for author profiles
Custom layouts for author profiles
Access control for the admin area
Remove PublishPress ads and branding
Priority, personal support