Hi
Here is updated rom for Cube LTE
http://www.needrom.com/download/myphone-cube-lte-1-0-3_root/
rom is rooted.
How to flash rom.
unpack zip (sp_flash tool & rom)
run sp flash tool a and select scatter file from folder CUBE_lte_1.0.3 (MT6735M_Android_scatter.txt)
next change download mode to firmware upgrade and click to download
turn of phone remove and insert battery back.
plug in phone to pc and wait to complet flash proces.
if finish flash proces, unplug phone a turn on.
enjoy root new rom. gapps included