Steve Puddick

This plugin prevents unauthorized admin users from damaging or compromising your website.
A common technique for hackers is to exploit vulnerabilities in your plugins or theme and try to create an unauthorized admin user for themselves. Once they have admin access they can do whatever they want to your website. They can deface it, display inappropriate content, or carry out many other malicious acts.
Restricted User Activity adds an extra step to the process of allowing Admin users to perform actions on your website. It achieves this by explicitly specifying valid Admin user ids in the wp-config.php file. Even if a hacker was able to create an Admin user for themselves, they won’t be able to perform any actions since their user id would not be in the valid user list.
Note: This plugin requires some technical knowledge about how the WordPress wp-config.php file works and basic PHP coding. A single line of code needs to be added to the wp-config.php file.

Restricted User Activity

Provides stricter controls for admin user creation and activity

andreyk

Just add usernames of those who are allowed to read your site, then no other person will be able to view it.

Trusted Only

Makes your site content visible only for several users who are in your trusted list.

Restricted User Activity vs Trusted Only