縦書きカクヨムパワーアップ is a free Chrome extension designed specifically for enhancing the reading experience on the Kakuyomu platform. This tool offers a variety of features including keyboard navigation for page turning, customizable background colors, fonts, text sizes, line spacing, and ruby size adjustments. Users can easily navigate through episodes and access a simple bookmarking system that syncs across devices using the same Google account.

The extension allows seamless control using arrow keys for page navigation and direct movement between episodes. A pop-up interface enables users to adjust visual settings with a color picker for background and text, along with a selection of fonts from standard options to Google Fonts. The bookmarking feature automatically saves the current page and position, making it convenient to continue reading from different devices without losing track of progress.