My Calculator - Decorator

This is not a typical calculator app.

1)be able to change the background of the key to your favorite image.

2)be able to be displayed Calculation process.

3)During input process, be able to delete numbers.

4)be able to calculate with parentheses.
for example: (10+5)x3+(30-5)

This app is very useful and fun calculator.

No ad. in Product version.