I need to make a hide and seek game for my students. They need to find WiFi signals from the school campus. They have to transmit WiFi signal, students have to find the signal with iPhone. This WiFi beacon has to be small and cheap and wireless (using external battery or AA batteries). It only has to send signal, it does not have to be able to connect with other iPhone users. It only has to send the signal not receive anything. Is there anything similar in the market?