Instead of aiming for a resolution, aim for an aspect ratio. There are a bunch of tutorials in that section of the site for that.
https://www.google.com/url?q=https://ww ... UcAAlINPbA
The iphone 5 has a 16:10 aspect ration where most Android devices have closer to a 16x9 aspect ration. Android screen rezes can go from 480x840 all the way to 1080P and no UHD with the G2. The iphone 5/5s has a 1136x640 screen res and the iPhone 4/4s. The iPhone 6 screen res hasn't been announced yet, but assumably it'll be two times the iPhone 5 display. Apple likes to keep things consistent.
It's easy to see why shooting for an aspect ratio makes more sense then a specific resolution now. Personally, the little I develop I tend to stick to 720P resolutions. I've found it to be a good medium for my purposes for the moment and it's a well supported aspect ratio.