Adaptive UICollectionView Cell Width
<p>I am new to collection view and Auto Layout and I have a problem making the cell sizes adapt to the various devices in the simulator. I am using the flow-layout and I set the sizes in the size inspector. The image I've provided shows the way I need the cells to look(canvas on the left iPhone5)on all devices. The iPhone4 display is good but the 6s is incorrect. 
Can someone please show me how this is done as I cannot find the precise information I am looking for.
Thanks</p>

<p>Also, I'm not sure why the iPhone5 doesn't display the cells on the preview section like the 4&amp;6 do..? any clues..?</p>

<p><a href="http://i.stack.imgur.com/LDDyM.png" rel="nofollow">screen shot1</a></p>