A lightweight, fully offline document viewer for Android. It's the app that opens when you tap a file in your Files app — no accounts, no ads, no network. It just opens documents and lets you read them.
| Format | Behavior |
|---|---|
Markdown (.md) |
Rendered with formatting |
Text (.txt) |
Shown as-is |
JSON (.json) |
Valid JSON is formatted with readable indentation; malformed content falls back to raw text |
CSV (.csv) |
Displayed as a scrollable table, including quoted commas, multiline cells, UTF-8, and Korean Excel encoding |
HTML (.html) |
Displayed with JavaScript and network disabled (offline) |
| Built-in renderer, page scrolling + pinch zoom | |
Images (.png .jpg .webp .gif) |
Fit-to-screen, pinch zoom, EXIF rotation, animated GIF |
Word (.docx) |
Converted to Markdown on the fly; export with "Save as MD" when you want |
- Adjustable text size (Aa) and per-document reading position memory
- Recent files list (documents opened via the in-app "Open file" picker)
- Gallery-style immersive view: tap to hide the status/navigation bars (images & PDF)
- Offline only — the app has no internet permission and never sends your documents anywhere
- View-only: it never modifies your original files (the DOCX "Save as MD" action is the only thing that writes a new file)
Distributed by sideloading (direct APK install), not via the Play Store.
- Download
OmniReader-x.y.z.apkfrom the latest release onto your Android device. - The first time, allow installing from unknown sources (Settings → Apps → Special app access → Install unknown apps → allow your browser/Files app).
- Tap the downloaded APK to install.
- From then on, tapping a document in your Files app will offer OmniReader in the "open with" list.
- Requirement: Android 10 (API 29) or newer.
- Official releases are always signed with the same key, so updates install over previous versions.
./gradlew assembleRelease # app/build/outputs/apk/release/app-release.apkWithout a release key (keystore.properties), the build falls back to debug
signing automatically. JDK 17 is required.
- Architecture & conventions: CLAUDE.md
- Work log, current state, known pitfalls: docs/HANDOFF.md
- Roadmap: docs/ROADMAP.md
MIT License — free to use, modify, and redistribute (keep the copyright notice). Provided as-is, without warranty.