Hi newtotinycore
You could try modifying the  /usr/bin/screenshot.sh  script to look like:
#!/bin/sh
[ -z ${DISPLAY} ] && echo "Requires X" &&  exit 1
editor /tmp/savename.txt
filename=`cat /tmp/savename.txt`.png
/bin/sh -c "sleep 1 && /usr/bin/imlib2_grab $filename"                          
exec popup "Screenshot saved to $HOME/$filename"When you take a screenshot, the editor will open. Type the filename you want, NO extension and NO carriage return.
Click the editors close button, click Save.  You will find  filename.png in your home directory. If you want the change
to survive a reboot, add the line   usr/bin/screenshot.sh   to your   /opt/.filetool.lst   file.