Help with layouts phone/tablet

Hi I’m new to Fuse and struggling with the following:

Displyaing sort of an image gallery that need to be 2 columns on phone and each column must be flexible width (50% each)

but on tablet it should be 3 columns and width of each columns fixed:


There is a new trigger coming in the next release called WhileWindowSize. It will allow you to do exactly these sorts of things.