Using terminal on Android with a touchscreen to edit files on a remote server

Search for the free Termux app and open it up. Install openssh using:

pkg install openssh

Wait for it to install, then type the following to login to your server:

ssh username@server.address

Navigate to the file you're after and open it with Vim, for example:

vi /etc/my.cnf

You then make use of the touch screen commands found at which make use of the Volume Up key mainly.