TYMap 4.2 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 software lies within Design & Photo Tools, more precisely Viewers & Editors. 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.
From the developer:
This is a GIS (Geographic Information System) software, you can use it to view shape file and usgs dem file, modify the attribute table etc.
You may want to check out more Mac applications, such as QuickShow OSX or Stone Studio, which might be similar to TYMap.