The 小説家になろう 縦書き表示 (Vertical Text Display for 小説家になろう) is a Chrome add-on developed by prhm0998. It is a free program in the Browsers category, specifically under Add-ons & Tools. This add-on aims to enhance the reading experience on the 小説家になろう (Narou) group site by converting the displayed works into vertical text format.

The main features of this add-on include the ability to convert the text into vertical orientation and the option to scroll through the text using the mouse wheel. Additionally, there are several optional features available, such as inverting the scroll direction, setting the text position, maximizing the text height, and converting full-width alphanumeric characters.

Overall, 小説家になろう 縦書き表示 provides a convenient way for users to read works on the 小説家になろう group site in a vertical text format, along with additional customization options to enhance the reading experience.