Here is my list of must haves (ones that are usually open on miThings). Some of these apps have their own pages in other spots since they are so good! I would say the "Both" column is the most accurate for required apps.
Of course there are others depending on location and mood but these (below) are the basics. Here are some other ones tho - iSamJackson, MLS, Cinnemark, Shatner Poetry....
The only order they are in is .... alphabetical!