TATEditor

An app for creating and editing vertical (tate-gaki) text.
With TATEditor, you can write novels, screenplays, and scenarios in vertical text with ruby (furigana) annotations on Android.
Sign in with your Google, Apple, or Microsoft account to sync texts and notes across iOS, Android, and the web.
Supports dark mode and Material You theming, and you can customize the editor with your own text and background colors.
Includes PDF export, so you can go from manuscript to print-ready data all within this app.

Key features:
- Auto-backup of texts while editing
- Incremental search and replace
- Regular expressions
- Copy, cut, and paste
- Real-time character counter
- Dark mode on/off
- Material You on/off
- Font switching
- Custom font file loading
- Text and background color customization
- Vertical text PDF export
- Ruby (furigana) display in Aozora Bunko format and more
- Support for emphasis dots and tate-chu-yoko (horizontal-in-vertical)
- Notes linked to projects and texts
- Chapter and episode management for serial works
- Auto-detection of character encoding for non-Unicode text import

Website: https://tateditor.app/
Author: https://twitter.com/496_
Dev blog: https://www.pixiv.net/fanbox/creator/13749983