UsersWP updates are provided via our WP Easy Updates (WPEU) plugin temporarily until UsersWP get published in wordpress.org plugin repository.
Once we publish the plugin in wordpress.org plugin repository, you can update the plugin as regular wp.org plugin.
However, keep in mind that you still require WPEU if you are using our UserWP addons.
You can download and install our WPEU plugin from here.
You can read about the WPEU plugin announcement here.