Download the app

One file, installed straight from here. No store account, no sign-up, and nothing to create before it works.

Download MeshDTN 1.0.15 for Android (60 MB)

What you are getting

Version 1.0.15, the current release.
Android 7.0 or newer (API 24), on a 64-bit ARM phone — which is every mainstream handset sold for years. It will not install on 32-bit-only devices or on an x86_64 emulator: the app needs a 64-bit address space for its image codec.
59,991,984 bytes. SHA-256:
9692ce388fc060d9aa7a91557b25428b10b3d6f872f344822bbe3b5335105e13

Installing it

Tap the download button above. Your browser will warn you that this kind of file can harm your device — that warning appears for every APK, from anyone.
Open the downloaded file. Android will ask whether to allow your browser to install unknown apps; allow it for that browser.
Tap Install, then open MeshDTN.

You can revoke that permission afterwards — Settings › Apps › your browser › Install unknown apps. The app does not need it again.

Then what

The app carries messages between phones on its own, over WiFi and over Bluetooth, with no radio at all. To reach further, flash a LoRa radio from the web flasher and pair it, or read Get started for the whole path from download to first carried message.

iPhone

Not yet. iOS is in scope and equal in priority, and the app is built to run there — but no iOS build has been published, so there is nothing here to pretend otherwise about.