Good news Latest Firmware has been released for Rikomagic MK802 IIIS, fixes below points,

Features:
1. Fixed MAC address changeable issue;
2. Added WIFI hotspot function;
3. Improvied USB connected with PC method:
power on the stick–>setting->select “usb connect with PC”->power off,pull out the stick.
Then connect the stick with computer,stick will default USB Slave method.
4. Flash first partition from 504MB changed ot 1.23GB.

Download link:

https://www.dropbox.com/s/2y4pftnnuuufniw/0120-MK802IIIS8B%28recovery%26update%29.rar

Password: geekbuying.com

Firmware upgrade guide, please check here

https://blog.geekbuying.com/index.php/2013/02/20/rikomagic-mk802-iiis-firmware-upgrade-guide/