Multiboot Android, Linux ISOs and Windows setup using GRUB
Using GRUB, a single USB flash drive can be deployed with mulitboot options of Android x86, Linux Mint, Manjaro Linux live boot ISO images and Windows 10 setup alongside at the same time. The advantage is; you need not to keep separate bootable DVD or USB drives for each OS. And, since the drive is FAT32 formatted, the remaining space on the USB media can be utilized for regular file storage.
A free USB pen drive (will get formatted, wiping existing contents) with enough storage capacity to hold all the ISO files.
Here, the target is a drive with 'MSDOS' partition table, 'FAT32' partition with a label (MULTIBOOT) and 'BOOT' flag set. You can use your own weapon of choice; any disk partitioning tool which can do the aforementioned tasks. Here, using Gparted for aesthetics!
Run Gparted as root. CAUTION:
Make sure of the selected drive to be the USB flash drive.
Create 'MSDOS' partition table.
Create New 'FAT32' partition and affix a label (eg. MULTIBOOT). FAT32 label should not exeed 11 characters limit or contain special charaters including dots and commas and lowercase is not supported.
Apply All Operations (Partioning and formating).
Right click on the partion, choose 'Manage Flags' and set 'BOOT' flag.