If you look at the stock Calculator on offer in Windows Phone 7, you are sure to notice that it is pretty similar to the one in Android, and is not lacking in functionality and features at all. Holding the device in portrait mode gives you a simple calculator, while tilting it sideways allows you to switch to scientific calculations. You might not feel the need for any other calculator app in the presence of the stock app, but that is only if you use your phone for calculations on occasion. However, if you are a Mathematics student or a businessman, you might want to take a look at some of the third-party calculator apps available in the Marketplace. One of the best in this category is Calculator². The app is a complete calculation suite, and acts a tool for unit conversion in addition to being a programmable, advanced calculator.
Calculator² starts off in the Basic calculator mode, which just lets you perform the most rudimentary of calculations, with one added feature. You can define any percentage as the default tax ratio in your country, so that you calculate prices of products quickly. The Scientific view is pretty similar to the one in the stock WP7 calculator, but it comes with the added bonus of storing the values of constants that are mostly used. The collection of constant values in Calculator² is so comprehensive that it comes with a search button of its own. Tapping the Func. in the Scientific menu will let you access all the predefined mathematical functions in the app.
For logical operations, there is the Program view of Calculator², and you will find all the popular number systems there, switching among which is really easy. The app stores all your past calculations in its Recent folder, and you can view this history there. From the Settings menu in Calculator², you can set notations, word size and precedence. Some cosmetic aspects of the app can be customized from this section as well. You might be able to find apps in the Marketplace that are nothing more than unit converters, but that functionality (along with currency conversion) is just a small part of the app, and can be accessed from the main grid.
Calculator² comes in a free, ad-supported version, although you can get rid of the ads by upgrading to the pro version of the app ($1.49). The web Marketplace link to both versions of Calculator² can be found below.