I'm very new to LiveCode and I love it

I'm testing mobGUI right now, because it seems to be the only way to build mobile Apps for multiple screen-resolutions, right now.
Ok, in mobGUI there a options for iPhone, iPhone retina, iPhone 5, iPhone 5 retina, iPad and custom.
My first question is: Why is there a 'iPhone 5' (w/o retina). There's no iPhone 5 without retina!? oO
And my second question is: How can I handle all devices at the same time? There's no option for iPad retina and if I'm using 'custom' as iPad retina, how can I handle Android devices at the same time?
And if I would build two stacks, one for iOS and one for Android, how can I handle the big value of different screen-resolutions on Android-devices?
Thank you
