You could have downloaded GUidCalc 4.3.1 for Mac from our software library for free. The application lies within Productivity Tools, more precisely Calculators. The actual developer of this free software for Mac is Unbearable Recordings.
From the developer:
GUIDCALC is a simple studio calculator available only for the Macintosh platform. It is a freeware software, smart, powerful, easy to use, efficient and also a professional tool. that helps you calculate. It is also a small size software with a friendly interface.
You may want to check out more software for Mac, such as Soap SAP, TINspireStudent or CASA-Intuition, which might be similar to GUidCalc.