Name: Gander
Author: Arjun Maniyani

Gander will not send your documents anywhere. Not as a promise it makes, but as a capability it does not have.

Every phone ships with a dozen half-viewers that bounce your documents through a cloud service to render them. Gander is the opposite: one small app that opens PDFs, Word documents, spreadsheets, slides, photos, video, audio, Markdown and code entirely on the device. It holds no permissions at all, including the one it would need to reach the network.

0: Permissions
0: Ads or trackers
8 MB: Download
100%: Offline

01 What it opens

PDF · Word (.docx) · Excel (.xlsx, .xls, .csv, .ods) · PowerPoint (.pptx) · Photos (JPG, PNG, WebP, GIF, HEIC, SVG and more) · Video (MP4, MKV, WebM, MOV and more) · Audio (MP3, FLAC, WAV, OGG and more) · Markdown · Text, JSON and code files.

In your file manager, tap any file and choose Open with > Gander. Or open Gander and pick a file, or grant it a folder to browse. It runs on Android 8.0 and up.

02 How the zero-permission trick works

Gander receives files through the Storage Access Framework and "Open with" intents, so Android hands it exactly the documents you chose and nothing else. That is why it needs no storage permission: it never goes looking.

Office formats render inside a locked-down WebView whose every request is intercepted. The rendering libraries load from the app's own assets and the document streams straight from the file you picked. No network stack is ever touched, and the app does not declare the INTERNET permission, so there is nothing to audit and nothing to take on trust.

The permission list is also checked at build time: the build fails if a dependency quietly adds one. And the app's own About screen asks Android what it requests and shows you the answer.

03 Get it

Google Play Coming shortly. This page will link it when the listing is live.
Download the APK Grab the latest from GitHub releases. One file works on every architecture, because the app ships no native code. Copy it to your phone and tap it.
Automatic updates without a store Install Obtainium and add https://github.com/mokshablr/gander as a source. It follows the tagged releases and updates Gander like a store would.
F-Droid Requested and in progress.

04 Verify what you installed

Every release is signed with the same key, so you can confirm an APK really came from this project rather than from someone who repackaged it. Obtainium can pin the fingerprint below, and for a file you have already downloaded:

apksigner verify --print-certs Gander-x.y.apk

SHA-256
5B:5C:F6:4A:94:23:7C:D5:F0:E0:85:76:00:38:BC:1C:EB:DF:18:DA:BA:5C:B3:EA:CA:7C:15:9F:22:A7:E2:4B

05 Honest about what it is not

It is a viewer, not an editor. It will not change your files.
Text inside PDFs is not searchable yet.
No legacy .doc or .ppt, only the modern formats.
Complicated PowerPoint decks render approximately, and charts inside spreadsheets are not drawn.
PDFs need Android System WebView 125 or newer. Gander says so plainly rather than showing you a blank page.

06 Who made it

Gander is made by Arjun Maniyani. It started as a small annoyance, which was that opening a PDF attachment on Android usually means handing it to something that wants an account first.

It is MIT licensed and the whole thing is readable at github.com/mokshablr/gander — issues and small pull requests are welcome. The zero-permission, zero-network property is the one thing that is not up for negotiation.