Hi 🎤🌵, that is one heck of a brutal review. When developing the app it was never my intention to waste anyone's time. Quite the opposite.I hope the following response may help your goal of efficiency. If not, I will gladly physically mail you a full cash refund if you haven't figured out how to get a refund through the system. Send me an email of your address. I'm not that way.There are a few common math app related things the app doesn't do:1) Show work (such as for homework)2) Rounding (Precision is more important to me. See more below)3) Square Roots (Mainly because of rounding. But may in the future return a decimal value as an answer in a rounded value.) Lots of irrational values.Number input key click usage:Whole numbers (blue outlined) are on the left half along with the negative, decimal, and repeating decimal start buttons.Fraction inputs have green outline.Fraction Numerators are in the upper right half.Fraction Denominators are in the bottom right half.Ex:1 + 1 = 22.25 - 1.1 = 1 3/201 1/2 - 3/4 = 3/4A simple click of a number button puts it in to the input at the top. I'm sure you've got that. In the Whole Number buttons you'll see units of measurements(UofM) in the upper right corners.To put a UofM after a numeric value you'll need to "long click" it(hold it down for a full second). Or a simple click of the grey "return as measurement" button (second from top left) after a numeric input.So:8ft 4 1/4in ÷ 4 = 25 1/16inor5.54cm - 3cm = 1inTo return a measurement of a different value:"Long click" the grey "in" button (second from left top grey button).So now:8ft 4 1/4in ÷ 4 = 63 527/800cmor5.54cm - 3cm = 2 27/50cmTo show a returned measurement (answer) to a visual representation (ruler screen), decimal value, fraction (decimal and fraction conversions), or "rounded" value. Click the "=" button one more time after a returned answer, a single input measurement, a single numeric value, or an empty input.On the "ruler screen" there are three synchronized things happening.changing a decimal updates the fraction and ruler.changing a fraction updates the decimal and ruler.Clicking the left or right half of the ruler updates the decimal and fraction values.When dealing with measurements this app does not round an answer. This way I can give an exact conversion between different types measurement. But I do offer the user to "Bump" to the nearest value of their choice.When in the ruler screen click the "Gear" button at the top right which will give you multiple options (even customizable) to round up or down to.When you have set what nearest bump value you want. swipe down the popup screen and click the left half of the ruler to go to the nearest value down. Or, click the right half of the ruler to bump it to the nearest larger value. I leave it to the user to choose what they want. Rounding is what I believe to be a 3rd/4th grade taught function that should be used at the users discretion.To change the ruler measurement that is displayed. Go back to the calculator screen and "long click" the grey 2nd from left top button to change the displayed ruler.If you have any questions or even suggestions of improvement please feel free to contact me by email. I'm more than willing to try and help with or improve the app.Thanks!Grant T.