This mockup is exactly what you need, a double screen presentation mockup for your mobile app designs. Drop your flat design in the photoshop smart object layers, save and return to your main file; this is all what you need to have your work showcased in this elegant way.
This fully layered PSD file allows you to show off your design. The PSD file allows you to change all elements and come with many customization options. Completely layered file with smart object.