One Hand Simple Calculator is a free iPhone app developed by Shigeo Fukuda. As the name suggests, this app is designed to be operated with just one hand, making it convenient for various situations.

The main feature of One Hand Simple Calculator is the ability to move the calculator keys to the left or right, allowing users to reach all buttons with ease. This solves the problem of buttons being too far and difficult to reach with just a thumb. Whether you hold your phone with your right or left hand, you can easily move the calculator keys to the desired side with a single touch.

In addition to its one-handed operation, this calculator app offers other useful features. Users can adjust the size of the calculator keys, making it customizable to their preferences. The app also visualizes calculation formulas as you input them, providing a clear understanding of the ongoing calculation. Furthermore, both the calculation results and formulas can be saved in history with just one tap, allowing for easy reference later on.

One Hand Simple Calculator keeps things simple by providing a straightforward interface without any special calculation buttons. It also offers a variety of theme colors to personalize the app's appearance. Additionally, there is a simple memo field available for temporary note-taking of calculation results.

Whether you need to quickly calculate something while holding a shopping cart at a store or gripping a handrail on a train, One Hand Simple Calculator is the perfect companion. Its centrally positioned calculator keys with spaces on both sides make it easy to use and navigate. Give it a try and experience the convenience of a one-handed calculator app!