LazyCaptcha is a small and lazy plugin to prevent bots from spamming your comments.
It generates a random image with an easy arithmetic task and checks if the result is correct after the comment is trasmitted.
It stores the tasks and results in the WordPress database and deletes them after use or two times a day using a wp-cron job.
It works perfectly on my sites, so I decided to publish it for others on WordPress.org.
Translations
LazyCaptcha comes in german and english. Feel free to translate it to other languages and send me the translation so I can include it into the translation repository