Eval is a simple graphing calculator that supports arithmetic expression evaluation. It can understand expressions such as log(1.5)+4/((1+sqrt(2))^2.5).
It supports multiple tabs, each with its own calculator.
It provides a rudimentary graphing capability, so you can for instance graph the formula: 1+sin(π/3+x/2) over a range you specify.
It provides a history of recent calculation results per tab.
Fixed a bug that affects iPad users.
iPyramid 
iRAW 
iSystem 