Window fit to screen format

I would like to know if there is a possibility to open every software window automatically fit to the screen format of the devterm (using clockwork os)

You could try making some scripts using xdotool (which you can install). See xdotool - fake keyboard/mouse input, window management, and more - semicomplete for some example usage.

A more complete way is to switch to a window manager that does this for you. There are several tiling window managers (dwm, i3, ratpoison, …) that will split your screen up evenly between all visible application windows. This is usually better than a simple always full screen type of system, because drag and drop and cut and paste becomes impossible if you enforce a policy of always full screen.

For myself I have xterm configured to use alt-enter for full screen. This makes it easy for me to pop in and out of typing activities, without sacrificing too much GUI work.