カクフル is a free Chrome add-on developed by kurokky that enhances the novel writing experience on カクヨム. This add-on provides convenient shortcut keys for adding furigana, emphasis, and separator lines while writing novels on カクヨム. With just a few keystrokes, users can easily insert the following elements into their text:

• Furigana: Press "Ctrl+Shift+," to add the "《》" brackets around the text.
• Emphasis: Press "Ctrl+Shift+." to add the "《《》》" brackets around the text.
• Separator Line: Press "Ctrl+Shift+¥" to insert the "｜" symbol.

Additionally, カクフル includes a helpful feature that checks for unclosed "》" brackets when users press "Ctrl+Shift+Enter." This ensures that authors do not forget to close their emphasis brackets.

Overall, カクフル is a valuable add-on for カクヨム users who want to streamline their novel writing process and enhance the readability of their works.