March 20, 2026
Bluetooth or Bleh-tooth?
Show HN: Red Grid Link – peer-to-peer team tracking over Bluetooth, no servers
Bluetooth squad tracker drops — fans cheer, skeptics yell “range of a loud yell”
TLDR: A new iOS app lets small teams track each other offline using phones only, no servers or cell service. The community loves the simplicity but battles over range: jokers say it’s only as far as a shout, radio fans push Meshtastic, and optimists eye Bluetooth long‑range as a possible fix.
Red Grid Link just crashed the party promising small teams can see each other on a map without cell service — no accounts, no servers, just phones talking directly. It leans on military-style grid coordinates (MGRS) and offline maps, and it’s live on iOS with Android “soon.” The app even keeps “ghost” teammates fading on your map when they wander out of range, and ships battery-sipping modes for long treks. Sounds like a backcountry fantasy, right? Cue the comments.
The thread immediately split into two camps: “this rules for close‑range squads” vs “Bluetooth can’t hang.” One joker summed it up as the “range of a loud yell,” and others pointed to the app’s own estimates — roughly 50–100 meters in open areas, 20–60 meters in woods — as a dealbreaker. Then came the radio crowd: “Why not just use Meshtastic?” (that hobbyist long-range radio network), claiming miles of coverage instead of meters. Defenders fired back that this is zero‑setup and phone‑only: perfect for trail buddies, SAR drills, and yes, Airsoft squads hungry for tactical cosplay. The plot twist? A pragmatic voice dropped a link to Bluetooth Long Range tech, hinting some newer phones might reach far further in the real world (details). Verdict from the peanut gallery: amazing idea for close‑quarters coordination — but the range debate is the whole show.
Key Points
- •Red Grid Link is an offline MGRS-based navigation and team coordination app available on iOS, with Android coming soon.
- •Field Link enables zero-configuration, infrastructure-free peer-to-peer sync over BLE plus AWDL (iOS) or Wi‑Fi Direct (Android) for 2–8 devices.
- •Data is protected with AES‑256‑GCM and ephemeral ECDH P‑256 keys, with Open/PIN/QR session authentication options.
- •Offline maps from USGS Topo and OpenTopoMap are cached as MBTiles with dynamic MGRS grid overlays.
- •The app offers four operational modes, 11 tactical tools, after‑action PDF exports, ghost markers with time‑decay, and low-power expedition modes (<3% or <2% battery/hr).