Aoirthoir

Converts plaintext URIs in posts or pages to clickable links. The Make Clickable plugin uses the WordPress make_clickable() function with an add_filter for the_content(). Install, activate and all of your plain text URIs will be clickable.

Make Clickable

Converts plaintext URIs in posts or pages to clickable links.

devoutpro

NoMore404 is a free WordPress plugin for redirection of 404 pages and simple firewall to block malicious hosts and URLs. 
All redirections are done via 301 redirection. 
You can mark any hosts and URLs to be blocked as malicious as well.

Nomore404 404 Redirection and Firewall

NoMore404 is a free WordPress plugin for redirection of 404 pages and simple firewall to block malicious hosts and URLs.

Make Clickable vs Nomore404 404 Redirection and Firewall