FYI, someone recently forked Graph89 into a 64bit version
https://github.com/eanema/graph89
Also on F-droid
It requests 0 permissions
If anyone is unhappy with the AOSP calculator and is familiar with those clunky old TI- hardware units, give it a try.
100x more useful than stock calc
Almost like an offline version of Wolfram Alpha.
Great for calculus-heavy stuff, symbolic math, plotting, etc.