A Listing of useful plugins
First - Security
2FA – Two Factor authorisation secures login by requiring a time based pin in addition to password. A weakness of WordPress is that usernames can be guessed quite easily from post data. Therefore 2FA is useful to prevent common attacks.
WP Fail2Ban Redux – On the underlying server I use Fail2Ban to block repeated attempts to login to various services (brute force attacks). This plugin extends that capability by pushing the IP address of possible attackers on the WordPress site to theserver and including them in the blocking system there – geeky but cool! Please note that we use the “Redux” version of this plugin since it has some improvements over the original and is NOT commercialised!
Later - Useful
Second - Performance
Autoptimize [sic] – We are always looking for best in class performance. regretfully a combination of “many plugins” and “complicated content” can slow down the site. One of the remedies we like to apply is optimisation of css, JS and images. This plugin helps doing this.