You can store your downloads in your account when you signup!
This stage has a great simple design to show off your app mock up. There is an iPhone 5s gray on a blue table. The iPhone 5s is set in landscape mode and will hold an image of 1136 by 640 pixels. Next to the iPhone, you get some fantastic Pantone style paint swatches making this design great for any interior design app or home-making app. The colors are all muted and your mock up will stand out really well against them.
Drag & drop not supported, but you can still upload via this input field: