The Good: CamRuler for iOS gives you fairly accurate measurements when you use it just right. The Bad: Poor interface controls get infuriating quickly. The lack of a back button means that if you make further adjustments, you're going to need to start over. The Bottom Line: CamRuler can work if you're willing to put in a lot of time on each measurement, but the interface for sizing and measuring is almost comically infuriating, making the current $1.99 price tag sting. CamRuler is a measurement app that uses common real-world objects in a photo to measure other objects in the photo, but it's more trouble than it's worth. \n\nWhen I first saw the app I thought it would be pretty useful -- people might be able to find the dimensions of their kitchen, for example, by taking a picture with a reference object. To be fair, when you can make it work, the app is quite accurate, but the interface keeps anything from being easy.\n\nIn my testing I tried a couple of objects within the app that have known measurements: a quarter coin and an 8.5x11 piece of paper. CamRuler has several objects you can use for reference in categories such as U.S. currency and standard paper sizes. You can also create and save reference objects of your own if you know their exact measurements.\n\n\n\nI selected a quarter as my reference within the app and placed a quarter on my desk. Then I put a pen next to it and snapped a picture within the app. In the next step, CamRuler has you resizing a circle (using pinch gestures) to match up with the surface area of the quarter. After matching the circle with the quarter, the next step is to match up both ends of a line to the length you're trying to measure, so I resized the line to the length of the pen and CamRuler told me how long it was. I checked with a tape measure afterward, and sure enough, CamRuler correctly measured the pen.