Inserting code at the end of footer using plugins

[veenuisthebest]

How do we do it?

Say I created a simple plugin on global_complete hook with:-

echo "Hello";

Now when I view the page its inserted at the top, even above doctype. I want Hello to be printed at the bottom most of the site (above </body>) using plugins. I don't want to do any find and replace for this small purpose.

Thanks