Most people associate editing documents and presentations on mobile with being a pain, but Google constantly aims to change that by adding new features to its Docs, Sheets, and Slides apps on Android. Case in point: the latest update for Google Docs features several helpful additions, including header and footer insertion, drag and drop text, as well as better control of images.
left: image adjustment. right: a header.
With images, you can now resize, move, and rotate them, as well as adjust text wrapping and border styles. When you're working on a picture, there's a new "Image" tab that you can utilize for further customization of your image's borders. Drag and drop text is pretty self-explanatory; just highlight the text you want to move, drag it, and drop it somewhere else. It's a bit difficult on a smartphone display, but it'll do in a pinch.
Lastly, headers and footers can now be inserted and edited on Android. If you tap on the uppermost part of the document, a very faint line should appear, indicating where the header is. (The same goes for the lowermost and the footer, obviously.)
This update has just begun to roll out, so it may not be on your device yet. However, if you're anxious to edit all of your essays on the fly, the latest Docs APK is already on APKMirror.