The Filmcalculator software is available in:

The Mac Appstore under the name Filmcalculator, (click the logo below)

In the Apple IOS/iPhone Appstore under the name: Filmcalc.

Other people try to use the name I have been using for over 20 years so be carefull that you select the red icon as shown above.

In the Android market you will find the App also under the name Filmcalc.

The Windows version can be downloaded here, tested for 30 days and then bought for 19,95 euro by using the button.