[APP] SlideMeter: Use your smartphone as tape measure
SlideMeter provides a way to measure the dimensions of near objects similar to classical meters. This is done by moving along the object's side you want to measure its length while holding the Hold button (e.g. measuring the width of a door, a carpet or a bed). To make more accurate measures, you can select the average check box which displays the mean of more than one measure of the dimension.
FREE at Google Play: please search for SlideMeter