Flipflop builds persistent Iroh tunnels for sharing files between your devices

A pairing-first take on file sharing

A file-sharing tool called Flipflop, published on GitHub under the handle andunieee, debuted on Hacker News as a Show HN post on 15 October. Its pitch is simple: establish a trusted tunnel between two or more devices once, and from that point on those devices can send each other files whenever they like.

According to the project's readme, the tunnel works over Bluetooth, a local network or the open internet, with the networking handled by Iroh, an open-source library built around direct connections between devices. Suggested uses include moving content between your own machines, sharing with family members in the same household, and sending links or plain text to people far away, not just files.

What persistence buys you

Most built-in sharing features are session-based: both devices need to be awake, discoverable and in the right place at the same moment, and the pairing evaporates once the transfer ends. Flipflop's model is closer to a standing relationship. Once two devices trust each other, a file, link or snippet can be pushed across at any time, regardless of which network each side is on. A Bluetooth link across the couch and an internet hop across the country are, per the readme, both fair game, and that single trust relationship spanning very different transports appears to be the main thing Iroh contributes, since the connection is tied to the devices rather than to one address or network.

Platforms and rough edges

The releases page offers builds for Linux, macOS and Windows, plus an Android APK. On Windows, users can either run the executable directly or install through a setup executable; the readme warns that the familiar Windows "protected your PC" SmartScreen prompt will appear, and it lays the blame on Microsoft in blunt terms. iOS is the notable absence, with the author saying Apple's restrictions make publishing an iOS build impossible.

For anyone who wants to build from source, the readme documents two paths: cargo run --release for a desktop build, and a just android-install task for Android, which requires cargo-apk alongside the Android SDK and NDK.

Why it matters

The persistent-tunnel idea is the interesting part of this launch. Cloud drives, email-to-self and chat apps all solve the same problem by routing everything through a third-party server and forcing a manual fetch on the other end. A device-to-device tunnel that survives network changes instead treats your devices as one continuous workspace, which is much closer to how people actually move between a phone, a laptop and a relative's machine over the course of a day.

It is also a practical showcase for Iroh-style networking, where one pairing covers every transport a pair of devices might encounter rather than demanding a separate mechanism for each.

The caveats are real, though. A tunnel that lets a paired device push anything at any time is a standing permission, and granting it is worth doing deliberately. The project is young, its desktop binaries trip operating-system warnings, and iOS users are left out entirely, so it is best read as an early, promising experiment with a model worth watching.