MonthlyCal 1.5.5 for Mac was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The software lies within Productivity Tools, more precisely Mind-mapping. This software for Mac OS X is an intellectual property of Fausto Ristagno. We recommend checking the downloaded files with any free antivirus.
From the developer:
MonthlyCal is a simple and colorful monthly calendar widget for OS X Yosemite. The application supports Gregorian's calendar and it is almost localized in every language. MonthlyCal gets settings automatically from your OS (Language, first weekday, etc.).
You may want to check out more software for Mac, such as TinyCal, TaskMate or NoteTaker, which might be similar to MonthlyCal.