Now if only I could calculate the log of something by pressing 'log' that would be nice.
If to the right of the 4 basic operators +, -, ×, ÷ you have a vertical strip (greenish in my case), you can slide it to the left and have access to various other operators/functions, including log.
Being based on the old SGI calculator, you can also slide any result to the left to get as many digits after the decimal point as you like.
e.g. slide in the extra ops, press π, then start sliding the 3.1415… result.
However, seeing as the calculator allows writing expressions with multiple operations, just shoving everything on the screen into ‘log()’ would be unreasonable, as one might want to provide the exact place for the logarithm themselves—so I guess the app does the most reasonable thing it can.