The app is the standard edition of Daily Talking Calculator.
Talk the tapped number and operator, talk the result of calculation.
From the log view, the user could browse the history calculation and listen the talking of all the expressions.
From the setting view, the user could select the volume and speed of the talking.
Support the expression (A+B)*C-D
Step 1: A+B
Step 2: (the result of step 1) * C
Step 3: (the result of step 2) - D