WiFi MAC Editor

In this tab you can edit your factory MAC address, given your device is rooted. If anything goes wrong (failure to connect) you can revert to original MAC address from the same screen.

Note that "original" MAC address is the one the app will read the first time you open this tab. If you modified your factory MAC address manually or using other apps there's no way to tell what is your original MAC address.

 

To be on the safe side, you can also use 3C Sensitive Backup to backup your WiFi settings (requires root).