Login Mandatory pages is a good handy and free solution for everyone who is looking to convert their simple pages to only accessible for logged in user.
It also provides setting to users to modify text on selected pages and also users can set their “login” page link.

Login Mandatory pages

• Easy to install
• Select the pages which you want to inaccessible for guest users
• You can set message on selected pages.
• You can also add a link of your website’s login page.