Wifitap is a proof of concept for communication over WiFi networks using traffic injection. It basically allows one to communicate over an open or WEP 802.11 network without being associated, thus bypassing any AP side restriction such as MAC address filtering or station isolation.
You can download it from the following link: https://packetstormsecurity.com/files/download/50754/wifitap-0.4.0.tgz
Source: https://packetstormsecurity.com/files/50754/wifitap-0.4.0.tgz.html