FlossWare Hotspot

Free Android app that shares your phone's mobile data via Wi-Fi — bypasses carrier hotspot restrictions without root. All apps work transparently.

The Problem

Carriers block the built-in Android hotspot unless you pay for a tethering add-on. You already pay for the data — this app lets you use it.

How It Works

Two apps work together — a Host on the phone sharing data, and a Client on the connecting device:

HOST PHONE                               CLIENT DEVICE
┌──────────────────────┐                 ┌──────────────────────┐
│  Wi-Fi Direct Group  │   P2P Wi-Fi     │                      │
│  Owner               │◄───────────────│  Connect to SSID     │
│                      │                 │                      │
│  Socks5Server :1080  │◄── SOCKS5 ─────│  VpnService + TUN    │
│                      │    (TCP+UDP)    │                      │
│  DnsRelay :5353      │◄── DNS ────────│  hev-socks5-tunnel   │
│                      │                 │  (native tun2socks)  │
│                      │                 │                      │
│  Cellular Data ──────┼──► Internet     │  All app traffic     │
│                      │                 │  captured by VPN     │
└──────────────────────┘                 └──────────────────────┘

Wi-Fi Direct creates a peer-to-peer Wi-Fi network — not carrier tethering. The phone becomes a Group Owner that other devices connect to like a regular Wi-Fi access point.

SOCKS5 Server runs on the host phone and forwards connections through mobile data. The carrier sees normal app traffic from the phone's own process — TTL-based tethering detection is inherently bypassed.

VPN Client runs on the connecting device, captures ALL traffic via Android's VpnService, and tunnels it through SOCKS5 using hev-socks5-tunnel — a native C library with a full userspace TCP/IP stack (lwIP). Every app works: browsers, social media, streaming, games, everything. TCP and UDP.

DNS Relay forwards hostname lookups through mobile data so connected devices can resolve addresses.

Requirements

• Android 8.0+ (API 26) on both devices
• Active mobile data connection on host phone
• No root required

Quick Start

Host phone (sharing data)

1. Install FlossWare Hotspot (host APK)
2. Grant permissions (location for Wi-Fi Direct)
3. Tap Start Hotspot
4. Share the displayed Wi-Fi name and password

Client device (connecting)

1. Install FlossWare Hotspot Client (client APK)
2. Connect to the displayed Wi-Fi network
3. Open FlossWare Hotspot Client
4. Tap Connect

All traffic is now routed through the host's mobile data.

Manual mode (no client app)

Apps that support SOCKS5 proxies can connect directly — configure 192.168.49.1:1080 as the SOCKS5 server (e.g., Firefox: Settings → Network → SOCKS5).

Building

git clone --recursive https://github.com/FlossWare/hotspot-android.git
cd hotspot-android
./gradlew assembleDebug

The --recursive flag is required — the client module includes hev-socks5-tunnel as a git submodule with nested dependencies (lwIP, libyaml, hev-task-system).

Prerequisites: Android SDK with NDK 27 installed. The NDK compiles the native tun2socks library for all four ABIs (arm64-v8a, armeabi-v7a, x86_64, x86).

APK outputs:

• Host: app/build/outputs/apk/debug/app-debug.apk
• Client: client/build/outputs/apk/debug/client-debug.apk

Run tests: ./gradlew test

Architecture

hotspot-android/
├── app/                              Host app (shares mobile data)
│   └── src/main/java/.../hotspot/
│       ├── proxy/
│       │   ├── Socks5Server.kt       SOCKS5 proxy (RFC 1928, server-side DNS)
│       │   └── DnsRelay.kt           UDP DNS forwarder
│       ├── service/
│       │   ├── HotspotService.kt     Foreground service orchestrating components
│       │   └── WifiDirectManager.kt  Wi-Fi Direct P2P group management
│       ├── model/
│       │   ├── HotspotState.kt
│       │   └── ConnectedDevice.kt
│       ├── viewmodel/
│       │   └── HotspotViewModel.kt
│       └── ui/
│           ├── HotspotScreen.kt      Single-screen Compose UI
│           └── components/
│
├── client/                           Client app (connecting device)
│   ├── src/main/java/.../client/
│   │   ├── service/
│   │   │   └── TunnelService.kt      VpnService — creates TUN, manages tunnel
│   │   ├── tunnel/
│   │   │   └── SocksTunnel.kt        YAML config + native library lifecycle
│   │   ├── model/
│   │   │   └── VpnState.kt
│   │   ├── viewmodel/
│   │   │   └── ClientViewModel.kt
│   │   └── ui/
│   │       └── ClientScreen.kt       Connect/disconnect UI
│   ├── src/main/java/hev/htproxy/
│   │   └── TProxyService.kt          JNI bridge to native library
│   └── src/main/jni/
│       └── hev-socks5-tunnel/        Native tun2socks (C, git submodule)
│           ├── src/                   SOCKS5 tunnel + JNI bindings
│           └── third-part/           lwIP, libyaml, hev-task-system
│
├── .github/workflows/
│   ├── android.yml                   CI: build + test + lint
│   ├── main.yml                      CD: auto-version on push to main
│   └── release.yml                   Release: APKs + GitHub Release
│
└── scripts/
    └── bump-version.sh               Manual version bump (X.Y format)

Design Decisions

• SOCKS5 (RFC 1928) with server-side DNS resolution — works with all TCP apps, not just HTTP
• Native tun2socks via hev-socks5-tunnel — full userspace TCP/IP stack (lwIP) handles TCP and UDP relay. ~300KB per ABI.
• addDisallowedApplication prevents VPN routing loops without root — the client app's own SOCKS5 connections bypass the TUN and go directly to the host via Wi-Fi Direct. Same pattern as WireGuard for Android.
• Thread-per-connection SOCKS5 server with bounded pool (4-32 threads) — simple and sufficient for phone-to-phone use
• Cellular-bound sockets — all outbound connections route through mobile data, never the P2P interface
• No Android framework dependencies in proxy/DNS code — fully unit-testable on JVM

Permissions

Host

Permission	Reason
ACCESS_FINE_LOCATION	Required by Android for Wi-Fi Direct (API 26-32)
NEARBY_WIFI_DEVICES	Wi-Fi Direct on API 33+
INTERNET	Forward traffic through cellular
FOREGROUND_SERVICE	Keep hotspot active in background

Client

Permission	Reason
INTERNET	Connect to SOCKS5 server
FOREGROUND_SERVICE	Keep VPN active
BIND_VPN_SERVICE	Android VPN consent (prompted once)

Location is never tracked, stored, or transmitted.

CI/CD

Every push to main builds both APKs, runs tests, auto-increments the minor version (X.Y format), and creates a git tag. Pushing a v* tag triggers a release build with both APKs attached to a GitHub Release.

License

Apache License 2.0