Open Source and Free Software

They check signatures to make sure they match, I believe. So using a software program is out unless it is actually using your signature.

Without a printer or a scanner, I am having a hard time thinking of a solution.

There is one way, you can sign your name on a piece of white paper using black ink, take a picture of it with your phone, email the picture to yourself so you can get it on your computer and then edit and crop the picture to be a certain size that you can insert to the ballot and place on the line where your signature goes.

I have done this in the past, but it is sketchy and takes time and knowledge of editing software.