Different note app / way to store often used formulas / how to start programming

[Angus]

Who guarantees a 100% correct functionality of a smartphone app - I mean if I do serious calculations leading to a faulty result...
I always had the hope that you pay for an as bug-free-as-possible device when going for a calculator. If you get that point.

Nevertheless I now got the feeling everybody understands what the other one meant.

And finally a push to my mes confusion :-)