Letterier
A Windows app for writing on illustrated stationery, arranging photos and text boxes, and finishing letters as PDF or print.
- Status
- Stable Release
- Version
- 2.1.0
- Updated
- October 29, 2026
- Platforms
- Windows 10 / 11 (64-bit)
- Languages
- Japanese / English
- License
- Apache-2.0
Turn your thoughts into a letter
Letterier is a Windows app for writing directly on illustrated stationery and arranging photos, illustrations, signatures, and independent text boxes. Choose from ten Japanese-inspired and ten Western-inspired stationery designs. Write Japanese vertically or horizontally, or English horizontally, on A4, B5, or postcard paper, then export PDF or print.
New in 2.1.0
- Vertical IME candidates: native MS-IME candidates follow vertical writing. Google Japanese Input conversion and Tab-expanded predictions are vertical; automatic suggestions remain horizontal.
- More room to read: fold the toolbar with Ctrl+F1. Read-only Reading view hides tools and side panels, with Fit width and Whole page options. Return with Esc or Back to editing.
- Page finishing: bottom-center Arabic page numbers and line-end alignment also appear in PDF and print output.
- Clearer editing: temporary undo/redo target highlights, improved bulk formatting, and more responsive typing and caret movement.
- Empty-line input fix: IME confirmation stays on the clicked empty line. Cancellation preserves the document; undo removes newly inserted empty lines together with the text. Cut also preserves text if clipboard copying fails.
- Updated illustrated Japanese and English PDF manuals are included in the portable ZIP and Store submission package.
Koibumi Penji is not bundled because its redistribution terms do not permit it.
Introduction and how-to videos
Japanese captions, Japanese-inspired background music and sound effects; no narration. The documents and names shown are fictional samples.
Introduction (1:58)
Watch the introduction on YouTube
How-to guide (16:00)
Watch the guide on YouTube. Chapters cover stationery, typing, formatting, paper, images and text boxes, pages, saving and recovery, PDF/print, and display options. Music sources and terms are listed in the video descriptions and acknowledgements.
Write, arrange, and keep
Text flows across pages. Set default fonts, format a selection, or change a page or document at once. Move images and text boxes between pages, resize, rotate, layer, change opacity, and control wrapping. Each text box has its own writing direction. Reusable custom stationery, background positioning, target line length, and font-aware rules are available.
Save letters as .binsen, keep local recovery data and protected history versions, and export history-inclusive .binsenbak backups. Recovery data is separate from saving a file and from a backup on another device. Keep important letters and their history backups on another medium too.
Downloads and manuals
Checked October 29, 2026: the direct-download ZIP on this page contains 2.1.0. Microsoft Store version 2.1.0 is also publicly available. Version 2.1.0 has been submitted to Vector and is awaiting publication. The existing Vector listing is awaiting the update. Until publication, use the ZIP on this page or Microsoft Store.
Extract the ZIP and run Letterier.exe. Microsoft WebView2 Runtime is required. Japanese and English PDF manuals are bundled. Use the English PDF button above or the Japanese PDF manual. The 2.1.0 direct distribution is a portable ZIP.
The direct-download EXE has a Y-TEC self-signed Authenticode signature and verified RFC 3161 timestamp. Windows or SmartScreen may warn about the self-signed certificate. It is not automatically added to the trusted certificate store. Microsoft Store packages receive the Store distribution signature.
ZIP SHA-256: 1a5c0366a5d73b02fa490f6d4e28457a584bf74b391370fe0a07826e4fe90629
SHA-256 list / Public certificate (CER)
Data and verification scope
Normal use is offline. Letters, images, history, and preferences stay on this PC. There is no advertising, analytics, authentication, or cloud sync. Choose Japanese or English UI, 21 color themes, and larger controls.
Version 2.1.0 was checked with automated tests and Windows hardware tests covering MS-IME, Google Japanese Input, empty-line input, saving, and PDF. Physical printing, a new Windows 10 run, and WACK were not performed this time. This is not a guarantee for every environment. See the verification scope and limitations. Screenshots show fictional 2.1.0 examples. Source code is available on GitHub.
Technologies
- Tauri 2
- React
- TypeScript
- Rust
Screenshots
Release history
Vertical IME candidates, a folding toolbar and Reading view. ZIP, manuals and two videos available. Store 2.1.0 published; Vector 2.1.0 submitted and awaiting publication.
The signed direct edition and GitHub tag v2.0.1 are public. Version 2.0.1 is available on both Microsoft Store and Vector.
The Microsoft Store 2.0.0 update is publicly available, with updated Japanese and English release notes and screenshots. The Vector update is awaiting publication.
Published the first stable Forge release with bilingual UI, 20 stationery designs, cross-page object dragging, signed builds, and Japanese and English manuals.
Rebalanced the stationery around the pale palette and diagonal composition of the 1.0.1 review build, while keeping the body area clear in portrait and landscape layouts.
Added the Japanese and English UI and manuals, 20 stationery designs, body-area-safe decoration, print improvements, and version consistency checks.
Published the first Letterier version with direct writing on paper, horizontal and vertical writing, stationery, arranged images and text boxes, PDF export, and printing.