Field service techs on the road have to travel light, but there are some tools in their belt that techs just can’t do without. Chainsaws and screwdrivers won’t soon be replaced by a mobile application, but new mobile applications allow techs to swap classics such as a measuring tape and a level for a phone or a tablet.

Screen shot 2014-04-10 at 9.05.24 AMOne free mobile app, EasyMeasure, is designed for the iPhone and can measure objects using the iPhone’s camera. The app uses a 3D camera overlay grid to calculate the height and width of any object, from tall buildings to coffee cups.

It’s a handy tool to double-check measurements, but don’t toss those measuring tapes just yet — especially if you work in an industry where precise measurements are critical. As the manufacturer warns on EasyMeasure’s iTunes page, “Measurements taken with EasyMeasure are not as accurate as measurements taken with standard tools. Do not use EasyMeasure for construction or other uses where inaccurate measurements could cause personal injury or property damage.”