If you are using Freeway Express then the easiest way to do this is to place an HTML item at the bottom of your page that will act as the footer. Because there are no layers in Express the footer item will always stay at the bottom of the page regardless of text size increasing in the browser. The one thing you will need to do is manually move the footer down the page in Freeway as your page size increases.
If you are using Pro and you want a footer that will always stick to the bottom of the page and not be overlapped by content above it then we recommend using a CSS flow layout. Take a look at the CSS Layout article for more information.