Rehber is a system that helps families locate lost loved ones during the five key days of Hajj. The system consists of a wearable device and supporting service designed to operate without a smartphone or mobile network. International pilgrims, especially children and the elderly, can easily find themselves lost within Mecca's massive crowds. Rehber provides a way to locate them. Each device has a range of up to 5 kilometers, significantly reducing infrastructure costs compared to other technologies such as Bluetooth or Wi-Fi. By operating free of mobile networks or smartphones, the system is both more resilient and easier for users to operate.