This is by far the most inaccurate measurement app I've used. It doesn't calculate the distance of what you're measuring correctly at all, or update the focus grid when the camera or objects in front of the camera move, even if you 'reset' it while the dot (or the whole screen) is on the new object you're trying to measure. It doesn't tell you how far you should stand away from the object you're measuring in order for it to get an accurate reading, and the further away it thinks the object is, the tinier the text is. (PS: The text disappears before you can actually read it in most cases. It stores in a History tab if you can get the buttons to work.) But I am certain the a 5-6cm object at most is not in the triple digits in cm--inches were not more accurate--not counting decimals, and RulerAR doesn't make accurate points measuring large or small objects. At least, not that I can see. There aren't measurement lines or points when measuring, just a teardrop looking thing where you end the point. I think parts of my table were 6-or-more digits in cm, but I couldn't read most of the table measurements because they were too small to show on my very tiny iPhone 12 Pro display. So tiny indeed. I honestly thought it stoppes measuring things because I couldn't see anything until I piled up measurement lines in bulk. I don't know what the trick is to using RulerAR, but if it can't tell you how to do it with the pre-made virtual measurements in the oh-so-unhelpful tutorial, I don't see why you think anybody would willingly pay for RulerAR . Probably why they try to take your money while you're pressing through all of the 'continue' buttons which honestly gave me red flags even before it gave me options that were worded in a way that made it seem like if I didn't pay upfront I couldn't continue to use RulerAR . What I did when I pressed 'continue' thinking RulerAR would just ask me to pay later: exited out of the pay screen where it asked me to doubt-tap the lock button to confirm the purchase. Props to everybody who manage to use this thing in their daily life. Please share your mental user manual.