Addism 1.2.5 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The following version: 1.1 is the most frequently downloaded one by the program users.
The actual developer of this software for Mac is Max Langer. This software is suitable for Mac OS X 10.10 or later. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. Addism for Mac lies within Productivity Tools, more precisely Calculators.
From the developer:
Addism is a great calculator for your Mac. It comes with a clean, intuitive user interface and lots of features. Addism displays the whole calculation and the result as you are typing, to provide you a complete overview over your calculation. You can use both mouse and your keyboard to calculate. Addism supports keyboard shortcuts for every function.
You may want to check out more software for Mac, such as Calculus, V-Planner or iUnit OSX, which might be similar to Addism.