☆. Calculator
According to user normal needs, we have remove other redundant operation buttons, and it has usage Record.
☆. Flashlight
Bright!Fast!Simple! Brightest Flashlight instantly ON, giving you the direction in the darkness.
☆. Currency Conversion
Easy to use,it provides up-to-date exchange rate information for over 135 currencies and countries!Great for when you travel abroad and need to calculate the latest exchange rates.
etc.
Source:
http://ismashphone.com/2012/12/toolkit-free-iphone-app.html