There are too many apps for NPR and PBS, for iPhone and iPad. I spend half an hour cleaning up all the apps. There are two pair of apps that are useful:

The official PBS (tv) apps published by PBS, for iPhone or iPad
The official NPR (radio) apps published by PBS for iPhone or iPad

The NPR (radio) apps both let you do live streaming or catch up on old shows. The Video program has selected content for viewing, but obviously no life streaming. These apps are confusing because they use the same icon for both iPhone and iPad, but the apps are different. On first sync I have both versions on the iPad and I need to launch them to figure out what is what.

There are other apps out there, the Public Radio Tuner will stream radio, and WBUR has their own apps. But I am not sure if they are necessary if you have the official apps.