RapidWeaver Stacks add-on info:
The ReFlow Stack is one of the best selling Stacks on defligra.com – but still use (a lot) because it was responsive even before the world went responsive. Responsive features has been added to take full advantage of the world we live in… and it's responsive.
ReFlow is an advanced grid with a lot of settings. You can use it out of the box but if you need to tweak something to your desire – you're covered.
Create a fixed width below 320 px (probably aprox 260 - 280 px) and have it reflow on all devices.
RapidWeaver, stacks, responsive, grid, columns, layout