The discussion centers around the search for effective iPhone calculator apps, particularly for graphing purposes. MathStudio is highlighted as a notable option, with users considering it as a potential replacement for traditional graphing calculators like the TI-83+. Concerns are raised about the use of smartphone calculators during tests due to cheating possibilities, with many preferring to stick to scientific calculators like the TI-36X Pro for exam situations. Other calculator options mentioned include the TI-89 Titanium, TI-nSpire CX CAS, and HP-50, with a preference for RPN calculators like the HP-41C and its iPhone emulation, i41CX. Additionally, WolframAlpha is recognized for its unmatched capabilities in calculations.