Point your phone at the wall you keep walking past. The print shows up at its real size, so you know before you buy.
Plan your wall: arrange prints over a sofa, a bed, or a photo of your room, all at true size.
Slower; needs a well-lit wall.
Your phone couldn't find the wall. Try more light, or a wall with a little texture or a picture on it, then tap View on your wall again.