hi kelly. another option.
i had the free app vlc media player stored in the cloud (on my other
fire) and went and downloaded to my 7" fire and gave it a try.
it has the playlist option i was looking for! it was right under my
nose. when it opened, asked if i wanted to connect to files on my sd
card. i did, and, all of the video files propagated to the app.
and, they play offline! cool beans.
stay well ... william