First, download the Kasty Imito MX1/MX2 20130204 rooted firmware from here or from here. Then follow this tutorial to flash the firmware image on Rikomagic MK802IIIS Stick via Rockchip Batch Tool v1.5.
Enjoy this new firmware!
Always keep in mind that this is not a review, just a first sight of this firmware. You have to test it more for another details, to see if it satisfies your needs.