Nearby — BLE / mDNS / SSDP

Nearby is a developer-focused reference Android app that scans for and decodes three of the most common discovery protocols on a wireless LAN: • Bluetooth Low Energy (BLE) — passive and active scanning, advertising payload decode, GATT service / characteristic enumeration on connect. • Multicast DNS / DNS-SD (RFC 6762) — service browse on 224.0.0.251:5353, including TXT record decode and IPv4 resolution. • SSDP / UPnP — M-SEARCH on 239.255.255.250:1900, NOTIFY parsing, and optional fetch of the device description XML from the LOCATION header. It is built as a teaching artefact for embedded firmware developers and Android engineers who want to see, in one place, what bytes a wireless device is actually emitting and how the platform parses them. Every screen in the app links back to the source file that produced it. Features • Live scanner with merged BLE / mDNS / SSDP feed and per-protocol filter chips. • RSSI sorting, MAC / vendor / name search. • Tap a device for a detailed view: hex dump of the raw scan record, decoded AD structures, GATT services with READ / WRITE / NOTIFY flags, mDNS PTR / SRV / TXT records, full SSDP description XML. • Favorites tab — pin devices to keep across scans and app restarts. Devices not currently visible are flagged "Not nearby". • Logs tab — chronological event stream of every scan callback, useful when debugging timing-sensitive devices. • Configurable scan window, scan interval, active-vs-passive mode, M-SEARCH MX, duplicate filtering — all persisted via DataStore. • Light / dark / system theming. • Share device info as a plain-text file via the Android share sheet. • Fully open source under MIT. No tracking, no analytics, no ads, no account. Source: https://github.com/rajeshpachaikani/nearby Permissions explained • Bluetooth scan / connect — required for BLE discovery and GATT inspection. We declare `usesPermissionFlags="neverForLocation"` so the OS never derives location from BLE results. • Location (Android 6 – 11 only) — legacy requirement for BLE scanning on older Android versions. Not requested on Android 12+. • Internet, network state, Wi-Fi state, multicast lock — required for mDNS and SSDP, both of which rely on multicast UDP on the local network. What this app does NOT do • Does not connect to the internet for any purpose other than receiving multicast traffic on your local Wi-Fi. • Does not collect, transmit or store any personal data. • Does not log RSSI, MACs or device names off-device. Suggested for • Embedded firmware engineers building BLE peripherals, Matter / Thread bridges, UPnP gateways or mDNS-advertised IoT devices. • Android engineers learning the BluetoothLeScanner / NsdManager APIs. • Network administrators auditing what is broadcasting on a network segment.