AlexCalc

AlexCalc is a scientific calculator with some neat features (note: also available as a web app at https://alexbarry.github.io/AlexCalc/ ):
* nicely formatted (LaTeX) equation display. This avoids the need to count brackets to make sure the equation was entered correctly. Also includes LaTeX code generation.
* complex number support, in rectangular or polar form (e.g. `3 + 4i` or `1 angle 90`)
* variable storage (e.g. `123 -> x` then `3*x^2 - 4*x + 5 -> y`)
* units in equations, and conversion (e.g. `1 inch * 3 ft to cm^2` or `sqrt(60 acre) - 100 ft`)
* can enter input by button presses, typing, or copy/pasting. Button presses are all converted to plaintext input for easy copy/pasting.
* equation display is simplified upon pressing enter. This means that when entering an equation, it is usually possible to look only at the LaTeX display and not the plaintext input: but when pressing enter, it will look nice. Redundant brackets are removed, including those that are needed for plaintext input (e.g. `(a + b)/(c + d)` can become "a + b" on the numerator and "c + d" on the denominator without brackets).
* light/dark themes
* previous input history can be accessed and edited by pressing "up" or "down" buttons.
* previous inputs/vars/recently used units preserved when the app is closed
* standard scientific calculator features, such as:
* trigonometric functions: sin, cos, tan, arcsin, arccos, arctan
* base 10 and natural logarithmic functions: log (base 10), ln (base e)
* `e`, `pi` constants, and square root function
* scientific notation input (e.g. `1.23E6` is 1.23 times 10^6)