Next Back Finish Start wizard Optimized Big buttons Simple In simple mode only basic functionality will be available from the main screen. Result is rounded up to 5 digits, degrees are used as the default angle units. Engineer In engineer mode special functions will be used on the main screen. Result is is not rounded and is presented in engineer notation, radians are used as the default angle units. Start wizard Excellent! Tap the button one more time to try again Tap the button below once to use 9 Drag from the center of the button up to use % Drag from the center of the button to the left to use sin Drag from the center of the button down to use ^2 Welcome Choose layout Choose mode Calculator in a separate window Drag button basics Almost done! Calculator++ is free and open-source: all the features are free of charge and source code can be found on github. There are several ways how you can help to make this app better: Donating money Translating Contributing source code