Counter is a number counting application. It is very useful for a quantity investigation, for example, counting wild birds and researching traffic. Tap the plus(+) button to increment the number. Tap the minus(-) button to decrease the number and tap the clear(C) button to reset the number to zero.
This application is one of the examples from the book titled "iPhone SDKの教科書 (iPhone SDK Textbook)" which shows how iPhone applications are constructed. The book is written in Japanese and published in Japan only.