Full page functionality has now been added. What this means is that you can now use rows as you would use your columns.
For instance, if you would like to display something by filling the screen you would use .row-12.
If you would like to split the screen into four horizontal sections then you would use .row-3 four times.
At present, this is only an experimental feature that I will hopefully be fully integrating soon. You can however check it out yourself via the GitHub repository.