Stock Graphic >> Product Mockup - iPhone 5s Vector Pack 18521 by Device Kits @ CreativeMarket
File Size: 1.3 MB; Requirements: Adobe CC+; Layered: Yes; DPI: 300 DPI; Vector: Yes.
Vector drawings of the iPhone 5s in its 3 color variations. Perfect for high-resolution presentations or print graphics, delivered as Adobe Illustrator CC files. The screen area is matched to 640 by 1136 pixels in Illustrator; you can paste your app design right into it.
Pasting these in Photoshop should work well enough, but you might want to experiment with exporting the devices from Illustrator itself at a higher resolution and then paste the resulting PNG into the Photoshop file in order to have better control over how the illustration is anti-aliased when rotated/resized (as Photoshop might render the identically sized vector surface areas differently depending on sub-pixel position and size of a vector smart object).
Keywords: illustration, iphone, iphone 5s, vector graphics.