The original GoTenna was a breakthrough for off-grid smartphone communications. The GoTenna Mesh is even better. As before, it's a portable, weatherproof gadget that pairs seamlessly to smartphones via Bluetooth-LE and uses a specialized app to let you send messages and share your location with other users. This time, however, it's operating on different, more robust frequencies, and using special networking tech to relay your message through other GoTennas, potentially doubling or even tripling its range. The result is the ability to communicate with loved ones at a distance of a mile or more, even in the wilderness, at large events where too many phones clog the towers, or in emergency situations where your cellular network has disappeared altogether.