The Category Image Plugin allow you to add image with category.
You can install Category Image directly from the WordPress admin panel.
Visit the Plugins > Add New and search for 'Category Image'. Click to install. Once installed, activate and it is functional.
Manual Installation Category Image plugin:
Download and unzip the file Upload the full extracted folder to the /wp-content/plugins/ directory * Maintain the directory structure of the archive (all extracted files should exist in 'wp-content/plugins/category-image/' Activate the plugin through the 'Plugins' menu in WordPress.
You're done! The Plugin ready to use according to the directions in the description.