Thanks Jimmy. At a previous job I asked ESRI about this and they said it was fine, there were just some minor restrictions of use. But I wanted to check again to see if it was still ok.
Looking at this link Create a map—Explorer for ArcGIS | ArcGIS , and then Step 1, it appears I need an organizational account to use Explorer (since it says there is a free trial, I assume it's paid after that). Trying to avoid paying for the moment.
Perhaps someone from ESRI will chime in here. Thanks again.