Range Finder is a lifestyle app that turns your iPhone into a measuring tape. It uses the phone's camera, height of the camera lens and iPhone tilt angle to calculate the distance, height, and width of the target object that you want to measure. This app uses angles to calculate the measurements, making it different from traditional measuring tapes.

Before using this app, you need to set the height of your iPhone lens from the ground. This height can be the height of your eyes, but it must be reset to the correct height if different people use the app. You must also stand on the same ground level as the target object to measure the distance accurately. To measure the height, you first need to get the distance and then lock it. You can then move the cross-point of the app to the target's top head and read the height result. To measure the width, you need to get the distance, lock it, and then move the big cross-point of the app to one end of the target object and the small cross-point to the other end to read the width result.

Overall, Range Finder is an easy-to-use app that can be helpful in measuring objects that are difficult to measure with traditional measuring tapes. However, it requires some practice and attention to detail to make accurate measurements.