From Tatsuo Sugama:
The second Usako app is lauched! Usako Calc is the cute calculator application. Cute rabbit Usako write on paper to calculate.Usako, well-known character on 'Usako Clock' appear in calculator app.You can use as ordinary calculator. When you push button, Usako write on paper to calculate hard.Usako can addition, subtraction, multiplication and division of decimal numbers, or negative numbers. You can copy to clipboard the calculation result, and you can paste to a notepad or another app.