Long story, I have a Raspberry Pi 3 Model B and the only device I own that can write a Raspbian image to MicroSD is my Android phone. I have copied the image from my laptop to my MicroSD, but I am puzzled as to how I can write the IMG to the MicroSD, as rooting will void my warranty. MicroSD is necessary since the Raspberry Pi will not boot from USB.
This is so easy copy ur IMG file to ur internal storage ,
download etchdroid from play store
select raw image or iso
(Do these steps after u have plug in ur scard)
select ur IMG file and ur scard
wait until it completes the progress
U can check the progress in the taskbar(notification) Done ....... The app is user friendly