You can store your downloads in your account when you signup!
A woman holds up her Nexus 7 over a sketchpad with her work at her office as if to take a photo. She is checking your app on the Nexus 7. She is holding the Nexus 7 in portrait view and the screen will hold a mockup of 800x1280px. To the left of the work book there are some brown books resting on the white desk stop. This stage is great for a scanning or photo app.
Drag & drop not supported, but you can still upload via this input field: