I'm designing iOS and Android apps full-time for over a year now. A couple of tips from me: - He's very right about previewing on the device. I like xScope better than Silkscreen, because it can stream anything, both file, or screen region, and overall it's a nice designer's utility belt. There's nothing like that for android, at least I haven't found anything that works, and Android needs this even more, because it…
My designer works in indesign, designs for 1x and scales up. As long as you know that images are 50%, it's much faster then doing everything in even pixels.
Sure, it can work 90% of the way, but I'd recommend designing only in PhotoShop - it is the tool, best optimised for that.