See the full post for details about Evernote for the iPad
Designing the new interface was a daunting task. First, we made an advanced prototype by cutting out a roughly-tablet-sized piece of cardboard, writing “iPad” on it, and carrying it around for a few days. We would bring it to meetings, hold it in different ways, and try to imagine what Evernote would feel like on this form factor. We looked pretty stupid and people made fun of us mercilessly. We printed out Photoshopped UI screens and taped them to the “iPad” to get an idea of font sizes and finger placement. We learned a lot.