You can store your downloads in your account when you signup!
A black Nexus 7 lies on a picnic table displaying your app. The Nexus 7 holds a mockup of 800x1280px. The table is a light brown wood. The Nexus 7 is tilted toward the left with the wooden slats parallel to it. This will work well for any type of app.
Drag & drop not supported, but you can still upload via this input field: