Best Online Diagram Software. Offline version for Windows and MacOs.

 I found the best diagram software available online and offline.

https://www.drawio.com/

Here it can be downloaded for macOS and Windows.

https://github.com/jgraph/drawio-desktop/releases/tag/v23.0.2

Shortcuts in Excel for Windows and MacOs

 I just found an exceljet.net. This is a cool site that shows the difference between the Windows shortcuts and MacOs shortcuts for MS Excel

https://exceljet.net/shortcuts

MacOS also has a cool program called Numbers but unfortunately, it is some problems with the edit .numbers format for Windows users