Donation bar in footer

Currently there isn't specifically such an extension (addon).

fast way;
in include/template/main.tpl

you can add a <div> with the code for the 'donation bar'

best way
or you can write an extension

that uses a hook (like for extension active topics by Grez) to place something where you need it...

What is the code the forum above uses? (paste it between [ code ] tags)