The best calculator for an accounting students~!

This is the best calculator I have ever used~!! I tried many calculator apps from apple app store but nothing like this one.

Pros:
There is a back space!!
It shows the result before I click the equal button.
It shows each calculation process.
I could save, copy, send email of the calculation process and the result.
I could save some calculation process as
Favorite.

Cons: none

Yeonjisforever about Calcbot 2, v2.1.2