Nice enough, but plotting & equations are $4.99 – Archimedes Calculator Review

I don't have a problem with freemium apps. I do have a problem with the dev completely disabling the two main features and calling it a free app without even listing an in-app purchase in the app description. I probably would be willing to pay the $5 if I could at least see how these "pro" features work.
Review by complectrum on Archimedes Calculator.