Let’s see if this is accurate – Measure Review

I tested 40 yards, on an actual football field In our school, 40 yards converted to feet is 120 feet But when I tried it I got 104-112 feet decimals , so I don’t know if this app is accurate or not, because sometimes when I use this app I set a starting place but the starting place changes and it goes closer.
Review by normal jame on Measure.