Though the ultimate destination will most likely be an LCD display, many apps begin their lives as nothing more than concept sketches on paper. And the next time you start doodling your brilliant app idea, this Pixel Ruler will ensure the various elements in its user interface are perfectly in proportion.
Along one edge of the stainless steel ruler is a series of tick marks indicating pixels—not inches or centimeters—at a scale of 150 pixels per inch. And along its length there are additional markers indicating smartphone, tablet, and laptop display sizing. It won't guarantee your idea becomes the next Angry Birds, but it should make the process of translating your app from paper to screen a heck of a lot easier.