To edit a Word Dynamo Word List on the app, follow these steps:
Tap on Browse My Word Lists from the sidebar menu.
Tap on the list you want to edit.
Tap on the edit icon with the pencil in the upper-right hand corner.
To delete a word, swipe to the left on the word you want to delete and then tap on the red delete button. To add a word, just enter the word in the text box next to the plus sign.