Do you want to measure an object by taking a photo (or two) of it? Now you can with the Photo Distance Measure app. Here is how it works.
1. Take a photo of an object or scene that you want to measure.
2. Take a second photo by moving your device paper length further back (i.e. 11 inches - the exact length of a regular piece of paper).
3. Line up the photos.
4. Thats it. You can move the cross-heirs to get the exact measurement of any two points in your scene.
How accurate are the results? That depends on how well you line up the photos, how well you follow the instructions, and so on. However, the results are usually within 10% accurate for objects less than 1 meter.