EtchDroid is an open-source application that helps you write images to USB drives, no root required.

You can use it to make a bootable GNU/Linux USB drive when your laptop is dead and you’re in the middle of nowhere.

Features

Supports raw disk images and most GNU/Linux distributions ISOs

Supports most DMG disk images (beta)

No root - everything is done within the bounds of the Android API

Free as in freedom

Planned features:

Write common GNU/Linux distro in streaming from the Internet without storing it on the device

Support for Windows installation ISO (will likely require root)

Support for Unetbootin-style image flashing

Screenshots