The present invention includes apparatuses, systems, and methods for peer group formation for mobile devices by proximity sensing. The described embodiments further include methods, systems, and apparatuses configured to easily establish an ad-hoc peer network in which each of the devices in the network automatically discovers and is connected to other devices in the network upon establishing a connection with at least one member of the ad-hoc network. The connection is established using a tap of NFC devices in the two wireless devices. Further, the wireless devices in the ad-hoc network may be divided into logical peer groups.