We've drafted this guide to help users install Flash Expander. It's been written for the Zgemma H9 series, but should work fine with other makes and models.
Installing Flash Expander to a USB stick will allow installation of both Kodi, Stalker and many other plugins in the H9 series (H9S, H9T, H9.2S, H9.2H).
EDIT 10/02/19: ZGEMMA H9S AND H9T MUST USE WHITE USB 2.0 PORT FOR FLASH EXPANDER.